diff --git a/pkg/analyzer/lib/src/dart/analysis/driver.dart b/pkg/analyzer/lib/src/dart/analysis/driver.dart
index 2cf4ffd..17a79a5 100644
--- a/pkg/analyzer/lib/src/dart/analysis/driver.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/driver.dart
@@ -761,7 +761,9 @@
         return UnspecifiedInvalidResult();
       },
       (externalLibrary) async {
-        var element = libraryContext.getLibraryElement(externalLibrary.uri);
+        final uri = externalLibrary.source.uri;
+        // TODO(scheglov) Check if the source is not for library.
+        var element = libraryContext.getLibraryElement(uri);
         return LibraryElementResultImpl(element);
       },
     );
@@ -1528,7 +1530,6 @@
       _saltForUnlinked,
       _saltForElements,
       featureSetProvider,
-      externalSummaries: _externalSummaries,
       fileContentCache: _fileContentCache,
     );
     _fileTracker = FileTracker(_logger, _fsState);
diff --git a/pkg/analyzer/lib/src/dart/analysis/file_state.dart b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
index a14226d..a6763f8 100644
--- a/pkg/analyzer/lib/src/dart/analysis/file_state.dart
+++ b/pkg/analyzer/lib/src/dart/analysis/file_state.dart
@@ -87,9 +87,9 @@
 
 /// A library from [SummaryDataStore].
 class ExternalLibrary {
-  final Uri uri;
+  final InSummarySource source;
 
-  ExternalLibrary._(this.uri);
+  ExternalLibrary._(this.source);
 }
 
 /// [FileContentOverlay] is used to temporary override content of files.
@@ -902,15 +902,6 @@
 
   final FeatureSetProvider featureSetProvider;
 
-  /// The optional store with externally provided unlinked and corresponding
-  /// linked summaries. These summaries are always added to the store for any
-  /// file analysis.
-  ///
-  /// While walking the file graph, when we reach a file that exists in the
-  /// external store, we add a stub [FileState], but don't attempt to read its
-  /// content, or its unlinked unit, or imported libraries, etc.
-  final SummaryDataStore? externalSummaries;
-
   /// Mapping from a URI to the corresponding [FileState].
   final Map<Uri, FileState> _uriToFile = {};
 
@@ -954,7 +945,6 @@
     this._saltForUnlinked,
     this._saltForElements,
     this.featureSetProvider, {
-    this.externalSummaries,
     required FileContentCache fileContentCache,
   }) : _fileContentCache = fileContentCache {
     _testView = FileSystemStateTestView(this);
@@ -1041,20 +1031,16 @@
   /// without a package name), or we don't know this package. The returned
   /// file has the last known state since if was last refreshed.
   Either2<FileState?, ExternalLibrary> getFileForUri(Uri uri) {
+    final uriSource = _sourceFactory.forUri2(uri);
+
     // If the external store has this URI, create a stub file for it.
     // We are given all required unlinked and linked summaries for it.
-    final externalSummaries = this.externalSummaries;
-    if (externalSummaries != null) {
-      String uriStr = uri.toString();
-      if (externalSummaries.uriToSummaryPath.containsKey(uriStr)) {
-        return Either2.t2(ExternalLibrary._(uri));
-      }
+    if (uriSource is InSummarySource) {
+      return Either2.t2(ExternalLibrary._(uriSource));
     }
 
     FileState? file = _uriToFile[uri];
     if (file == null) {
-      Source? uriSource = _sourceFactory.forUri2(uri);
-
       // If the URI cannot be resolved, for example because the factory
       // does not understand the scheme, return the unresolved file instance.
       if (uriSource == null) {
diff --git a/runtime/vm/compiler/assembler/assembler_arm.cc b/runtime/vm/compiler/assembler/assembler_arm.cc
index aa43b50..67f8fb8 100644
--- a/runtime/vm/compiler/assembler/assembler_arm.cc
+++ b/runtime/vm/compiler/assembler/assembler_arm.cc
@@ -2810,6 +2810,10 @@
   }
 }
 
+void Assembler::LoadImmediate(Register rd, Immediate value, Condition cond) {
+  LoadImmediate(rd, value.value(), cond);
+}
+
 void Assembler::LoadImmediate(Register rd, int32_t value, Condition cond) {
   Operand o;
   if (Operand::CanHold(value, &o)) {
diff --git a/runtime/vm/compiler/assembler/assembler_arm.h b/runtime/vm/compiler/assembler/assembler_arm.h
index 419dca2..00dc85b 100644
--- a/runtime/vm/compiler/assembler/assembler_arm.h
+++ b/runtime/vm/compiler/assembler/assembler_arm.h
@@ -47,6 +47,16 @@
 
 namespace compiler {
 
+class Immediate : public ValueObject {
+ public:
+  explicit Immediate(int32_t value) : value_(value) {}
+
+  int32_t value() const { return value_; }
+
+ private:
+  const int32_t value_;
+};
+
 // Instruction encoding bits.
 enum {
   H = 1 << 5,   // halfword (or byte)
@@ -803,6 +813,10 @@
 
   void CallCFunction(Address target) { Call(target); }
 
+  void CallCFunction(Register target, Condition cond = AL) {
+    blx(target, cond);
+  }
+
   // Add signed immediate value to rd. May clobber IP.
   void AddImmediate(Register rd, int32_t value, Condition cond = AL) {
     AddImmediate(rd, rd, value, cond);
@@ -867,6 +881,7 @@
   // These three do not clobber IP.
   void LoadPatchableImmediate(Register rd, int32_t value, Condition cond = AL);
   void LoadDecodableImmediate(Register rd, int32_t value, Condition cond = AL);
+  void LoadImmediate(Register rd, Immediate value, Condition cond = AL);
   void LoadImmediate(Register rd, int32_t value, Condition cond = AL);
   // These two may clobber IP.
   void LoadSImmediate(SRegister sd, float value, Condition cond = AL);
diff --git a/runtime/vm/compiler/assembler/assembler_arm64.h b/runtime/vm/compiler/assembler/assembler_arm64.h
index e11ed94..3e79152 100644
--- a/runtime/vm/compiler/assembler/assembler_arm64.h
+++ b/runtime/vm/compiler/assembler/assembler_arm64.h
@@ -1790,7 +1790,15 @@
   }
   void Call(const Code& code) { BranchLink(code); }
 
-  void CallCFunction(Address target) { Call(target); }
+  // Clobbers LR.
+  void CallCFunction(Address target) {
+    Call(target);
+  }
+  void CallCFunction(Register target) {
+#define __ this->
+    CLOBBERS_LR({ blr(target); });
+#undef __
+  }
 
   void AddImmediate(Register dest, int64_t imm) {
     AddImmediate(dest, dest, imm);
@@ -2054,6 +2062,9 @@
   void LoadUniqueObject(Register dst, const Object& obj);
   // Note: the function never clobbers TMP, TMP2 scratch registers.
   void LoadImmediate(Register reg, int64_t imm);
+  void LoadImmediate(Register reg, Immediate imm) {
+    LoadImmediate(reg, imm.value());
+  }
 
   void LoadDImmediate(VRegister reg, double immd);
   void LoadQImmediate(VRegister reg, simd128_value_t immq);
@@ -2080,6 +2091,9 @@
     LoadImmediate(TMP, immediate);
     Push(TMP);
   }
+  void PushImmediate(Immediate immediate) {
+    PushImmediate(immediate.value());
+  }
   void CompareObject(Register reg, const Object& object);
 
   void ExtractClassIdFromTags(Register result, Register tags);
diff --git a/runtime/vm/compiler/assembler/assembler_ia32.cc b/runtime/vm/compiler/assembler/assembler_ia32.cc
index 2ead117..b5f2b99 100644
--- a/runtime/vm/compiler/assembler/assembler_ia32.cc
+++ b/runtime/vm/compiler/assembler/assembler_ia32.cc
@@ -9,6 +9,7 @@
 
 #include "vm/class_id.h"
 #include "vm/compiler/assembler/assembler.h"
+#include "vm/compiler/backend/locations.h"
 #include "vm/cpu.h"
 #include "vm/instructions.h"
 #include "vm/tags.h"
diff --git a/runtime/vm/compiler/assembler/assembler_ia32.h b/runtime/vm/compiler/assembler/assembler_ia32.h
index 48f6a49..b97296c 100644
--- a/runtime/vm/compiler/assembler/assembler_ia32.h
+++ b/runtime/vm/compiler/assembler/assembler_ia32.h
@@ -21,6 +21,7 @@
 #include "vm/pointer_tagging.h"
 
 namespace dart {
+
 namespace compiler {
 
 class Immediate : public ValueObject {
@@ -747,6 +748,10 @@
     }
   }
 
+  void LoadImmediate(Register reg, Immediate immediate) {
+    LoadImmediate(reg, immediate.value());
+  }
+
   void LoadDImmediate(XmmRegister dst, double value);
 
   void Drop(intptr_t stack_elements);
@@ -874,6 +879,10 @@
 
   void CallCFunction(Address target) { Call(target); }
 
+  void CallCFunction(Register target) {
+    call(target);
+  }
+
   void Jmp(const Code& code);
   void J(Condition condition, const Code& code);
 
diff --git a/runtime/vm/compiler/assembler/assembler_riscv.cc b/runtime/vm/compiler/assembler/assembler_riscv.cc
index 863adf4..0c1caab 100644
--- a/runtime/vm/compiler/assembler/assembler_riscv.cc
+++ b/runtime/vm/compiler/assembler/assembler_riscv.cc
@@ -2719,6 +2719,10 @@
   jalr(RA);
 }
 
+void Assembler::Call(Register target) {
+  jalr(target);
+}
+
 void Assembler::AddImmediate(Register rd,
                              Register rs1,
                              intx_t imm,
diff --git a/runtime/vm/compiler/assembler/assembler_riscv.h b/runtime/vm/compiler/assembler/assembler_riscv.h
index ac1e920..914301b 100644
--- a/runtime/vm/compiler/assembler/assembler_riscv.h
+++ b/runtime/vm/compiler/assembler/assembler_riscv.h
@@ -929,9 +929,13 @@
       CodeEntryKind entry_kind = CodeEntryKind::kNormal);
 
   void Call(Address target);
+  void Call(Register target);
   void Call(const Code& code) { JumpAndLink(code); }
 
   void CallCFunction(Address target) { Call(target); }
+  void CallCFunction(Register target) {
+    Call(target);
+  }
 
   void AddImmediate(Register dest, intx_t imm) {
     AddImmediate(dest, dest, imm);
diff --git a/runtime/vm/compiler/assembler/assembler_x64.h b/runtime/vm/compiler/assembler/assembler_x64.h
index 6680a77..9f3fb6e 100644
--- a/runtime/vm/compiler/assembler/assembler_x64.h
+++ b/runtime/vm/compiler/assembler/assembler_x64.h
@@ -1246,7 +1246,7 @@
   // offset is not yet known and needs therefore relocation to the right place
   // before the code can be used.
   //
-  // The neccessary information for the "linker" (i.e. the relocation
+  // The necessary information for the "linker" (i.e. the relocation
   // information) is stored in [UntaggedCode::static_calls_target_table_]: an
   // entry of the form
   //
diff --git a/runtime/vm/compiler/backend/constant_propagator.cc b/runtime/vm/compiler/backend/constant_propagator.cc
index 63528f15..51af8e2 100644
--- a/runtime/vm/compiler/backend/constant_propagator.cc
+++ b/runtime/vm/compiler/backend/constant_propagator.cc
@@ -752,15 +752,7 @@
   SetValue(instr, non_constant_);
 }
 
-void ConstantPropagator::VisitEnterHandleScope(EnterHandleScopeInstr* instr) {
-  SetValue(instr, non_constant_);
-}
-
-void ConstantPropagator::VisitExitHandleScope(ExitHandleScopeInstr* instr) {
-  // Nothing to do.
-}
-
-void ConstantPropagator::VisitAllocateHandle(AllocateHandleInstr* instr) {
+void ConstantPropagator::VisitCCall(CCallInstr* instr) {
   SetValue(instr, non_constant_);
 }
 
diff --git a/runtime/vm/compiler/backend/flow_graph_compiler.cc b/runtime/vm/compiler/backend/flow_graph_compiler.cc
index 04712ef..32c36ac 100644
--- a/runtime/vm/compiler/backend/flow_graph_compiler.cc
+++ b/runtime/vm/compiler/backend/flow_graph_compiler.cc
@@ -3606,7 +3606,6 @@
   }
 }
 
-
 // The assignment to loading units here must match that in
 // AssignLoadingUnitsCodeVisitor, which runs after compilation is done.
 static intptr_t LoadingUnitOf(Zone* zone, const Function& function) {
diff --git a/runtime/vm/compiler/backend/il.cc b/runtime/vm/compiler/backend/il.cc
index 98a44f1..8e50cc3 100644
--- a/runtime/vm/compiler/backend/il.cc
+++ b/runtime/vm/compiler/backend/il.cc
@@ -4,6 +4,7 @@
 
 #include "vm/compiler/backend/il.h"
 
+#include "platform/assert.h"
 #include "vm/bit_vector.h"
 #include "vm/bootstrap.h"
 #include "vm/compiler/aot/dispatch_table_generator.h"
@@ -6800,101 +6801,6 @@
   __ Comment("EmitReturnMovesEnd");
 }
 
-static Location FirstArgumentLocation() {
-#ifdef TARGET_ARCH_IA32
-  return Location::StackSlot(0, SPREG);
-#else
-  return Location::RegisterLocation(CallingConventions::ArgumentRegisters[0]);
-#endif
-}
-
-LocationSummary* EnterHandleScopeInstr::MakeLocationSummary(
-    Zone* zone,
-    bool is_optimizing) const {
-  LocationSummary* summary =
-      new (zone) LocationSummary(zone, /*num_inputs=*/0,
-                                 /*num_temps=*/0, LocationSummary::kCall);
-  summary->set_out(0,
-                   Location::RegisterLocation(CallingConventions::kReturnReg));
-  return summary;
-}
-
-void EnterHandleScopeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  ASSERT(kEnterHandleScopeRuntimeEntry.is_leaf());
-
-  Location arg_loc = FirstArgumentLocation();
-  __ EnterCFrame(arg_loc.IsRegister() ? 0 : compiler::target::kWordSize);
-  NoTemporaryAllocator no_temp;
-  compiler->EmitMove(arg_loc, Location::RegisterLocation(THR), &no_temp);
-  __ CallCFunction(
-      compiler::Address(THR, compiler::target::Thread::OffsetFromThread(
-                                 &kEnterHandleScopeRuntimeEntry)));
-  __ LeaveCFrame();
-}
-
-LocationSummary* ExitHandleScopeInstr::MakeLocationSummary(
-    Zone* zone,
-    bool is_optimizing) const {
-  LocationSummary* summary =
-      new (zone) LocationSummary(zone, /*num_inputs=*/0,
-                                 /*num_temps=*/0, LocationSummary::kCall);
-  return summary;
-}
-
-void ExitHandleScopeInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  ASSERT(kEnterHandleScopeRuntimeEntry.is_leaf());
-
-  Location arg_loc = FirstArgumentLocation();
-  __ EnterCFrame(arg_loc.IsRegister() ? 0 : compiler::target::kWordSize);
-  NoTemporaryAllocator no_temp;
-  compiler->EmitMove(arg_loc, Location::RegisterLocation(THR), &no_temp);
-  __ CallCFunction(
-      compiler::Address(THR, compiler::target::Thread::OffsetFromThread(
-                                 &kExitHandleScopeRuntimeEntry)));
-  __ LeaveCFrame();
-}
-
-LocationSummary* AllocateHandleInstr::MakeLocationSummary(
-    Zone* zone,
-    bool is_optimizing) const {
-  LocationSummary* summary =
-      new (zone) LocationSummary(zone, /*num_inputs=*/1,
-                                 /*num_temps=*/0, LocationSummary::kCall);
-
-  Location arg_loc = FirstArgumentLocation();
-  // Assign input to a register that does not conflict with anything if
-  // argument is passed on the stack.
-  const Register scope_reg =
-      arg_loc.IsStackSlot() ? CallingConventions::kSecondNonArgumentRegister
-                            : arg_loc.reg();
-
-  summary->set_in(kScope, Location::RegisterLocation(scope_reg));
-  summary->set_out(0,
-                   Location::RegisterLocation(CallingConventions::kReturnReg));
-  return summary;
-}
-
-Representation AllocateHandleInstr::RequiredInputRepresentation(
-    intptr_t idx) const {
-  ASSERT(idx == kScope);
-  return kUnboxedIntPtr;
-}
-
-void AllocateHandleInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
-  ASSERT(kEnterHandleScopeRuntimeEntry.is_leaf());
-
-  Location arg_loc = FirstArgumentLocation();
-  __ EnterCFrame(arg_loc.IsRegister() ? 0 : compiler::target::kWordSize);
-  if (arg_loc.IsStackSlot()) {
-    NoTemporaryAllocator no_temp;
-    compiler->EmitMove(arg_loc, locs()->in(kScope), &no_temp);
-  }
-  __ CallCFunction(
-      compiler::Address(THR, compiler::target::Thread::OffsetFromThread(
-                                 &kAllocateHandleRuntimeEntry)));
-  __ LeaveCFrame();
-}
-
 LocationSummary* RawStoreFieldInstr::MakeLocationSummary(
     Zone* zone,
     bool is_optimizing) const {
@@ -7049,6 +6955,126 @@
   __ MoveRegister(out, THR);
 }
 
+LocationSummary* CCallInstr::MakeLocationSummaryInternal(
+    Zone* zone,
+    const RegList temps) const {
+  LocationSummary* summary =
+      new (zone) LocationSummary(zone, /*num_inputs=*/InputCount(),
+                                 /*num_temps=*/Utils::CountOneBitsWord(temps),
+                                 LocationSummary::kNativeLeafCall);
+
+  intptr_t reg_i = 0;
+  for (intptr_t reg = 0; reg < kNumberOfCpuRegisters; reg++) {
+    if ((temps & (1 << reg)) != 0) {
+      summary->set_temp(reg_i,
+                        Location::RegisterLocation(static_cast<Register>(reg)));
+      reg_i++;
+    }
+  }
+
+  summary->set_in(TargetAddressIndex(),
+                  Location::RegisterLocation(
+                      CallingConventions::kFirstNonArgumentRegister));
+
+  const auto& argument_locations =
+      native_calling_convention_.argument_locations();
+  for (intptr_t i = 0, n = argument_locations.length(); i < n; ++i) {
+    const auto& argument_location = *argument_locations.At(i);
+    if (argument_location.IsRegisters()) {
+      const auto& reg_location = argument_location.AsRegisters();
+      ASSERT(reg_location.num_regs() == 1);
+      summary->set_in(i, reg_location.AsLocation());
+    } else if (argument_location.IsFpuRegisters()) {
+      UNIMPLEMENTED();
+    } else if (argument_location.IsStack()) {
+      summary->set_in(i, Location::Any());
+    } else {
+      UNIMPLEMENTED();
+    }
+  }
+  const auto& return_location = native_calling_convention_.return_location();
+  ASSERT(return_location.IsRegisters());
+  summary->set_out(0, return_location.AsLocation());
+  return summary;
+}
+
+CCallInstr::CCallInstr(
+    Zone* zone,
+    const compiler::ffi::NativeCallingConvention& native_calling_convention,
+    InputsArray* inputs)
+    : Definition(DeoptId::kNone),
+      zone_(zone),
+      native_calling_convention_(native_calling_convention),
+      inputs_(inputs) {
+#ifdef DEBUG
+  const intptr_t num_inputs =
+      native_calling_convention.argument_locations().length() + 1;
+  ASSERT(num_inputs == inputs->length());
+#endif
+  for (intptr_t i = 0, n = inputs_->length(); i < n; ++i) {
+    SetInputAt(i, (*inputs_)[i]);
+  }
+}
+
+Representation CCallInstr::RequiredInputRepresentation(intptr_t idx) const {
+  if (idx < native_calling_convention_.argument_locations().length()) {
+    const auto& argument_type =
+        native_calling_convention_.argument_locations().At(idx)->payload_type();
+    ASSERT(argument_type.IsExpressibleAsRepresentation());
+    return argument_type.AsRepresentation();
+  }
+  ASSERT(idx == TargetAddressIndex());
+  return kUnboxedFfiIntPtr;
+}
+
+void CCallInstr::EmitParamMoves(FlowGraphCompiler* compiler,
+                                Register saved_fp,
+                                Register temp0) {
+  if (native_calling_convention_.StackTopInBytes() == 0) {
+    return;
+  }
+
+  ConstantTemporaryAllocator temp_alloc(temp0);
+  compiler::ffi::FrameRebase rebase(zone_, /*old_base=*/FPREG,
+                                    /*new_base=*/saved_fp,
+                                    /*stack_delta=*/0);
+
+  __ Comment("EmitParamMoves");
+  const auto& argument_locations =
+      native_calling_convention_.argument_locations();
+  for (intptr_t i = 0, n = argument_locations.length(); i < n; ++i) {
+    const auto& argument_location = *argument_locations.At(i);
+    if (argument_location.IsRegisters()) {
+      const auto& reg_location = argument_location.AsRegisters();
+      ASSERT(reg_location.num_regs() == 1);
+      const Location src_loc = rebase.Rebase(locs()->in(i));
+      const Representation src_rep = RequiredInputRepresentation(i);
+      compiler->EmitMoveToNative(argument_location, src_loc, src_rep,
+                                 &temp_alloc);
+    } else if (argument_location.IsFpuRegisters()) {
+      UNIMPLEMENTED();
+    } else if (argument_location.IsStack()) {
+      const Location src_loc = rebase.Rebase(locs()->in(i));
+      const Representation src_rep = RequiredInputRepresentation(i);
+      __ Comment("Param %" Pd ": %s %s -> %s", i, src_loc.ToCString(),
+                 RepresentationToCString(src_rep),
+                 argument_location.ToCString());
+      compiler->EmitMoveToNative(argument_location, src_loc, src_rep,
+                                 &temp_alloc);
+    } else {
+      UNIMPLEMENTED();
+    }
+  }
+  __ Comment("EmitParamMovesEnd");
+}
+
+Representation CCallInstr::representation() const {
+  const auto& return_type =
+      native_calling_convention_.return_location().payload_type();
+  ASSERT(return_type.IsExpressibleAsRepresentation());
+  return return_type.AsRepresentation();
+}
+
 // SIMD
 
 SimdOpInstr::Kind SimdOpInstr::KindForOperator(MethodRecognizer::Kind kind) {
@@ -7206,7 +7232,7 @@
   Representation inputs[4];
 };
 
-// Make representaion from type name used by SIMD_OP_LIST.
+// Make representation from type name used by SIMD_OP_LIST.
 #define REP(T) (kUnboxed##T)
 static const Representation kUnboxedBool = kTagged;
 static const Representation kUnboxedInt8 = kUnboxedInt32;
diff --git a/runtime/vm/compiler/backend/il.h b/runtime/vm/compiler/backend/il.h
index c4192ba..9f7562f 100644
--- a/runtime/vm/compiler/backend/il.h
+++ b/runtime/vm/compiler/backend/il.h
@@ -428,9 +428,7 @@
   M(SpecialParameter, kNoGC)                                                   \
   M(ClosureCall, _)                                                            \
   M(FfiCall, _)                                                                \
-  M(EnterHandleScope, kNoGC)                                                   \
-  M(ExitHandleScope, kNoGC)                                                    \
-  M(AllocateHandle, kNoGC)                                                     \
+  M(CCall, kNoGC)                                                              \
   M(RawStoreField, kNoGC)                                                      \
   M(InstanceCall, _)                                                           \
   M(PolymorphicInstanceCall, _)                                                \
@@ -5349,50 +5347,53 @@
   DISALLOW_COPY_AND_ASSIGN(FfiCallInstr);
 };
 
-class EnterHandleScopeInstr : public TemplateDefinition<0, NoThrow> {
+// Has the target address in a register passed as the last input in IL.
+class CCallInstr : public Definition {
  public:
-  EnterHandleScopeInstr() {}
+  CCallInstr(
+      Zone* zone,
+      const compiler::ffi::NativeCallingConvention& native_calling_convention,
+      InputsArray* inputs);
 
-  DECLARE_INSTRUCTION(EnterHandleScope)
+  DECLARE_INSTRUCTION(CCall)
 
-  virtual Representation representation() const { return kUnboxedIntPtr; }
+  LocationSummary* MakeLocationSummaryInternal(Zone* zone,
+                                               const RegList temps) const;
+
+  // Input index of the function pointer to invoke.
+  intptr_t TargetAddressIndex() const {
+    return native_calling_convention_.argument_locations().length();
+  }
+
+  virtual intptr_t InputCount() const { return inputs_->length(); }
+  virtual Value* InputAt(intptr_t i) const { return inputs_->At(i); }
+  virtual bool MayThrow() const { return false; }
+
   virtual bool ComputeCanDeoptimize() const { return false; }
-  virtual bool HasUnknownSideEffects() const { return false; }
+
+  virtual bool HasUnknownSideEffects() const { return true; }
+
+  virtual bool CanCallDart() const { return false; }
+
+  virtual Representation RequiredInputRepresentation(intptr_t idx) const;
+  virtual Representation representation() const;
+
+  void EmitParamMoves(FlowGraphCompiler* compiler,
+                      Register saved_fp,
+                      Register temp0);
 
   PRINT_OPERANDS_TO_SUPPORT
 
  private:
-  DISALLOW_COPY_AND_ASSIGN(EnterHandleScopeInstr);
-};
+  virtual void RawSetInputAt(intptr_t i, Value* value) {
+    (*inputs_)[i] = value;
+  }
 
-class ExitHandleScopeInstr : public TemplateInstruction<0, NoThrow> {
- public:
-  ExitHandleScopeInstr() {}
+  Zone* const zone_;
+  const compiler::ffi::NativeCallingConvention& native_calling_convention_;
+  InputsArray* inputs_;
 
-  DECLARE_INSTRUCTION(ExitHandleScope)
-
-  virtual bool ComputeCanDeoptimize() const { return false; }
-  virtual bool HasUnknownSideEffects() const { return false; }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ExitHandleScopeInstr);
-};
-
-class AllocateHandleInstr : public TemplateDefinition<1, NoThrow> {
- public:
-  explicit AllocateHandleInstr(Value* scope) { SetInputAt(kScope, scope); }
-
-  enum { kScope = 0 };
-
-  DECLARE_INSTRUCTION(AllocateHandle)
-
-  virtual Representation RequiredInputRepresentation(intptr_t idx) const;
-  virtual Representation representation() const { return kUnboxedIntPtr; }
-  virtual bool ComputeCanDeoptimize() const { return false; }
-  virtual bool HasUnknownSideEffects() const { return false; }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(AllocateHandleInstr);
+  DISALLOW_COPY_AND_ASSIGN(CCallInstr);
 };
 
 // Populates the untagged base + offset outside the heap with a tagged value.
diff --git a/runtime/vm/compiler/backend/il_arm.cc b/runtime/vm/compiler/backend/il_arm.cc
index 8794fb4..d42f1c2 100644
--- a/runtime/vm/compiler/backend/il_arm.cc
+++ b/runtime/vm/compiler/backend/il_arm.cc
@@ -1714,6 +1714,33 @@
   FunctionEntryInstr::EmitNativeCode(compiler);
 }
 
+#define R(r) (1 << r)
+
+LocationSummary* CCallInstr::MakeLocationSummary(Zone* zone,
+                                                 bool is_optimizing) const {
+  constexpr Register saved_fp = CallingConventions::kSecondNonArgumentRegister;
+  return MakeLocationSummaryInternal(zone, (R(saved_fp)));
+}
+
+#undef R
+
+void CCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  const Register saved_fp = locs()->temp(0).reg();
+  const Register temp0 = TMP;
+
+  __ MoveRegister(saved_fp, FPREG);
+
+  const intptr_t frame_space = native_calling_convention_.StackTopInBytes();
+  __ EnterCFrame(frame_space);
+
+  EmitParamMoves(compiler, saved_fp, temp0);
+
+  const Register target_address = locs()->in(TargetAddressIndex()).reg();
+  __ CallCFunction(target_address);
+
+  __ LeaveCFrame();
+}
+
 LocationSummary* OneByteStringFromCharCodeInstr::MakeLocationSummary(
     Zone* zone,
     bool opt) const {
diff --git a/runtime/vm/compiler/backend/il_arm64.cc b/runtime/vm/compiler/backend/il_arm64.cc
index 6c1cc4f..2dfcd42 100644
--- a/runtime/vm/compiler/backend/il_arm64.cc
+++ b/runtime/vm/compiler/backend/il_arm64.cc
@@ -1577,6 +1577,41 @@
   FunctionEntryInstr::EmitNativeCode(compiler);
 }
 
+#define R(r) (1 << r)
+
+LocationSummary* CCallInstr::MakeLocationSummary(Zone* zone,
+                                                 bool is_optimizing) const {
+  constexpr Register saved_csp = kAbiFirstPreservedCpuReg;
+  ASSERT(IsAbiPreservedRegister(saved_csp));
+  return MakeLocationSummaryInternal(zone, (R(saved_csp)));
+}
+
+#undef R
+
+void CCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  const Register saved_fp = TMP2;
+  const Register temp0 = TMP;
+  const Register saved_csp = locs()->temp(0).reg();
+
+  __ MoveRegister(saved_fp, FPREG);
+
+  const intptr_t frame_space = native_calling_convention_.StackTopInBytes();
+  __ EnterCFrame(frame_space);
+  ASSERT(IsAbiPreservedRegister(saved_csp));
+  __ mov(saved_csp, CSP);
+  __ mov(CSP, SP);
+
+  EmitParamMoves(compiler, saved_fp, temp0);
+
+  const Register target_address = locs()->in(TargetAddressIndex()).reg();
+  __ CallCFunction(target_address);
+
+  // We don't use the DartSP, we leave the frame after this immediately.
+  // However, we need set CSP to a 16 byte aligned value far above the SP.
+  __ mov(CSP, saved_csp);
+  __ LeaveCFrame();
+}
+
 LocationSummary* OneByteStringFromCharCodeInstr::MakeLocationSummary(
     Zone* zone,
     bool opt) const {
diff --git a/runtime/vm/compiler/backend/il_ia32.cc b/runtime/vm/compiler/backend/il_ia32.cc
index 1915491..1513ce0 100644
--- a/runtime/vm/compiler/backend/il_ia32.cc
+++ b/runtime/vm/compiler/backend/il_ia32.cc
@@ -1248,6 +1248,34 @@
   FunctionEntryInstr::EmitNativeCode(compiler);
 }
 
+#define R(r) (1 << r)
+
+LocationSummary* CCallInstr::MakeLocationSummary(Zone* zone,
+                                                 bool is_optimizing) const {
+  constexpr Register saved_fp = CallingConventions::kSecondNonArgumentRegister;
+  constexpr Register temp0 = CallingConventions::kFfiAnyNonAbiRegister;
+  static_assert(saved_fp < temp0, "Unexpected ordering of registers in set.");
+  return MakeLocationSummaryInternal(zone, (R(saved_fp) | R(temp0)));
+}
+
+#undef R
+
+void CCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  const Register saved_fp = locs()->temp(0).reg();
+  const Register temp0 = locs()->temp(1).reg();
+
+  __ MoveRegister(saved_fp, FPREG);
+  const intptr_t frame_space = native_calling_convention_.StackTopInBytes();
+  __ EnterCFrame(frame_space);
+
+  EmitParamMoves(compiler, saved_fp, temp0);
+
+  const Register target_address = locs()->in(TargetAddressIndex()).reg();
+  __ CallCFunction(target_address);
+
+  __ LeaveCFrame();
+}
+
 static bool CanBeImmediateIndex(Value* value, intptr_t cid) {
   ConstantInstr* constant = value->definition()->AsConstant();
   if ((constant == NULL) ||
diff --git a/runtime/vm/compiler/backend/il_printer.cc b/runtime/vm/compiler/backend/il_printer.cc
index f901a37f..8f983bd 100644
--- a/runtime/vm/compiler/backend/il_printer.cc
+++ b/runtime/vm/compiler/backend/il_printer.cc
@@ -1286,8 +1286,20 @@
   }
 }
 
-void EnterHandleScopeInstr::PrintOperandsTo(BaseTextBuffer* f) const {
-  f->AddString("<enter handle scope>");
+void CCallInstr::PrintOperandsTo(BaseTextBuffer* f) const {
+  f->AddString(" target_address=");
+  InputAt(TargetAddressIndex())->PrintTo(f);
+
+  const auto& argument_locations =
+      native_calling_convention_.argument_locations();
+  for (intptr_t i = 0; i < argument_locations.length(); i++) {
+    const auto& arg_location = *argument_locations.At(i);
+    f->AddString(", ");
+    InputAt(i)->PrintTo(f);
+    f->AddString(" (@");
+    arg_location.PrintTo(f);
+    f->AddString(")");
+  }
 }
 
 void NativeReturnInstr::PrintOperandsTo(BaseTextBuffer* f) const {
diff --git a/runtime/vm/compiler/backend/il_riscv.cc b/runtime/vm/compiler/backend/il_riscv.cc
index 00b0cdb..73580e9 100644
--- a/runtime/vm/compiler/backend/il_riscv.cc
+++ b/runtime/vm/compiler/backend/il_riscv.cc
@@ -1426,13 +1426,7 @@
 
 #define R(r) (1 << r)
 
-LocationSummary* FfiCallInstr::MakeLocationSummary(Zone* zone,
-                                                   bool is_optimizing) const {
-  LocationSummary* summary = MakeLocationSummaryInternal(
-      zone, is_optimizing,
-      (R(CallingConventions::kSecondNonArgumentRegister) |
-       R(CallingConventions::kFfiAnyNonAbiRegister) | R(CALLEE_SAVED_TEMP2)));
-
+static void RemapA3A4A5(LocationSummary* summary) {
   // A3/A4/A5 are unavailable in normal register allocation because they are
   // assigned to TMP/TMP2/PP. This assignment is important for reducing code
   // size. We can't just override the normal blockage of these registers because
@@ -1450,6 +1444,18 @@
       summary->set_in(i, Location::RegisterLocation(T5));
     }
   }
+}
+
+#define R(r) (1 << r)
+
+LocationSummary* FfiCallInstr::MakeLocationSummary(Zone* zone,
+                                                   bool is_optimizing) const {
+  LocationSummary* summary = MakeLocationSummaryInternal(
+      zone, is_optimizing,
+      (R(CallingConventions::kSecondNonArgumentRegister) |
+       R(CallingConventions::kFfiAnyNonAbiRegister) | R(CALLEE_SAVED_TEMP2)));
+
+  RemapA3A4A5(summary);
   return summary;
 }
 
@@ -1759,6 +1765,47 @@
   FunctionEntryInstr::EmitNativeCode(compiler);
 }
 
+#define R(r) (1 << r)
+
+LocationSummary* CCallInstr::MakeLocationSummary(Zone* zone,
+                                                 bool is_optimizing) const {
+  constexpr Register saved_fp = CallingConventions::kSecondNonArgumentRegister;
+  constexpr Register temp0 = CallingConventions::kFfiAnyNonAbiRegister;
+  static_assert(saved_fp < temp0, "Unexpected ordering of registers in set.");
+  LocationSummary* summary =
+      MakeLocationSummaryInternal(zone, (R(saved_fp) | R(temp0)));
+  RemapA3A4A5(summary);
+  return summary;
+}
+
+#undef R
+
+void CCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  const Register saved_fp = locs()->temp(0).reg();
+  const Register temp0 = locs()->temp(1).reg();
+
+  // Beware! Do not use CODE_REG/TMP/TMP2/PP within FfiCallInstr as they are
+  // assigned to A2/A3/A4/A5, which may be in use as argument registers.
+  __ set_constant_pool_allowed(false);
+
+  __ MoveRegister(saved_fp, FPREG);
+
+  const intptr_t frame_space = native_calling_convention_.StackTopInBytes();
+  __ EnterCFrame(frame_space);
+
+  // Also does the remapping A3/A4/A5.
+  EmitParamMoves(compiler, saved_fp, temp0);
+
+  const Register target_address = locs()->in(TargetAddressIndex()).reg();
+  __ CallCFunction(target_address);
+
+  __ LeaveCFrame();
+
+  // PP is a volatile register, so it must be restored even for leaf FFI calls.
+  __ RestorePoolPointer();
+  __ set_constant_pool_allowed(true);
+}
+
 LocationSummary* OneByteStringFromCharCodeInstr::MakeLocationSummary(
     Zone* zone,
     bool opt) const {
diff --git a/runtime/vm/compiler/backend/il_x64.cc b/runtime/vm/compiler/backend/il_x64.cc
index b6b58ce..55fc995 100644
--- a/runtime/vm/compiler/backend/il_x64.cc
+++ b/runtime/vm/compiler/backend/il_x64.cc
@@ -1444,6 +1444,34 @@
   FunctionEntryInstr::EmitNativeCode(compiler);
 }
 
+#define R(r) (1 << r)
+
+LocationSummary* CCallInstr::MakeLocationSummary(Zone* zone,
+                                                 bool is_optimizing) const {
+  constexpr Register saved_fp = CallingConventions::kSecondNonArgumentRegister;
+  return MakeLocationSummaryInternal(zone, (R(saved_fp)));
+}
+
+#undef R
+
+void CCallInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
+  const Register saved_fp = locs()->temp(0).reg();
+  const Register temp0 = TMP;
+
+  // TODO(http://dartbug.com/47778): If we knew whether the stack was aligned
+  // at this point, we could omit having a frame.
+  __ MoveRegister(saved_fp, FPREG);
+
+  const intptr_t frame_space = native_calling_convention_.StackTopInBytes();
+  __ EnterCFrame(frame_space);
+
+  EmitParamMoves(compiler, saved_fp, temp0);
+  const Register target_address = locs()->in(TargetAddressIndex()).reg();
+  __ CallCFunction(target_address);
+
+  __ LeaveCFrame();
+}
+
 static bool CanBeImmediateIndex(Value* index, intptr_t cid) {
   if (!index->definition()->IsConstant()) return false;
   const Object& constant = index->definition()->AsConstant()->value();
diff --git a/runtime/vm/compiler/backend/redundancy_elimination.cc b/runtime/vm/compiler/backend/redundancy_elimination.cc
index c9245a5..7d37d1f 100644
--- a/runtime/vm/compiler/backend/redundancy_elimination.cc
+++ b/runtime/vm/compiler/backend/redundancy_elimination.cc
@@ -1876,7 +1876,7 @@
 
     // 1) Populate 'gen' sets with places which are initialized at each basic
     // block. Optimize lazy initializer calls within basic block and
-    // figure out if there are lazy intializer calls left to optimize.
+    // figure out if there are lazy initializer calls left to optimize.
     bool has_lazy_initializer_calls = false;
     for (BlockIterator block_it = graph_->reverse_postorder_iterator();
          !block_it.Done(); block_it.Advance()) {
@@ -4351,7 +4351,6 @@
   if (MayHaveVisibleEffect(current) || current->CanDeoptimize() ||
       current == block->last_instruction() || current->IsMaterializeObject() ||
       current->IsCheckStackOverflow() || current->IsReachabilityFence() ||
-      current->IsEnterHandleScope() || current->IsExitHandleScope() ||
       current->IsRawStoreField()) {
     return false;
   }
diff --git a/runtime/vm/compiler/compiler_pass.cc b/runtime/vm/compiler/compiler_pass.cc
index 2ea7890..f6a4dd3 100644
--- a/runtime/vm/compiler/compiler_pass.cc
+++ b/runtime/vm/compiler/compiler_pass.cc
@@ -311,6 +311,7 @@
   INVOKE_PASS(TypePropagation);
   INVOKE_PASS(WidenSmiToInt32);
   INVOKE_PASS(SelectRepresentations_Final);
+  INVOKE_PASS(CSE);
   INVOKE_PASS(TypePropagation);
   INVOKE_PASS(TryCatchOptimization);
   INVOKE_PASS(EliminateEnvironments);
diff --git a/runtime/vm/compiler/ffi/native_location.cc b/runtime/vm/compiler/ffi/native_location.cc
index ef92266..ca039d3 100644
--- a/runtime/vm/compiler/ffi/native_location.cc
+++ b/runtime/vm/compiler/ffi/native_location.cc
@@ -318,7 +318,12 @@
 }
 
 void NativeStackLocation::PrintTo(BaseTextBuffer* f) const {
-  f->Printf("S%+" Pd, offset_in_bytes_);
+  if (base_register_ != SPREG) {
+    f->Printf("S(%s)+%" Pd, RegisterNames::RegisterAbiName(base_register_),
+              offset_in_bytes_);
+  } else {
+    f->Printf("S+%" Pd, offset_in_bytes_);
+  }
   PrintRepresentations(f, *this);
 }
 
diff --git a/runtime/vm/compiler/ffi/native_type.cc b/runtime/vm/compiler/ffi/native_type.cc
index 6838082..a6cf2e4 100644
--- a/runtime/vm/compiler/ffi/native_type.cc
+++ b/runtime/vm/compiler/ffi/native_type.cc
@@ -8,6 +8,7 @@
 #include "platform/globals.h"
 #include "vm/class_id.h"
 #include "vm/compiler/ffi/abi.h"
+#include "vm/compiler/runtime_api.h"
 #include "vm/constants.h"
 #include "vm/zone_text_buffer.h"
 
@@ -583,6 +584,23 @@
                                                            Representation rep) {
   return *new (zone) NativePrimitiveType(fundamental_rep(rep));
 }
+
+const NativeFunctionType* NativeFunctionType::FromUnboxedRepresentation(
+    Zone* zone,
+    intptr_t num_arguments,
+    Representation representation) {
+  const auto& intptr_type =
+      compiler::ffi::NativePrimitiveType::FromUnboxedRepresentation(
+          zone, representation);
+  auto& argument_representations =
+      *new (zone) ZoneGrowableArray<const compiler::ffi::NativeType*>(
+          zone, num_arguments);
+  for (intptr_t i = 0; i < num_arguments; i++) {
+    argument_representations.Add(&intptr_type);
+  }
+  return new (zone)
+      compiler::ffi::NativeFunctionType(argument_representations, intptr_type);
+}
 #endif  // !defined(DART_PRECOMPILED_RUNTIME) && !defined(FFI_UNIT_TESTS)
 
 const char* NativeType::ToCString(Zone* zone,
diff --git a/runtime/vm/compiler/ffi/native_type.h b/runtime/vm/compiler/ffi/native_type.h
index a3a03bd..e85f091 100644
--- a/runtime/vm/compiler/ffi/native_type.h
+++ b/runtime/vm/compiler/ffi/native_type.h
@@ -404,6 +404,13 @@
                      const NativeType& return_type)
       : argument_types_(argument_types), return_type_(return_type) {}
 
+#if !defined(DART_PRECOMPILED_RUNTIME) && !defined(FFI_UNIT_TESTS)
+  static const NativeFunctionType* FromUnboxedRepresentation(
+      Zone* zone,
+      intptr_t num_arguments,
+      Representation representation);
+#endif
+
   const NativeTypes& argument_types() const { return argument_types_; }
   const NativeType& return_type() const { return return_type_; }
 
diff --git a/runtime/vm/compiler/frontend/kernel_to_il.cc b/runtime/vm/compiler/frontend/kernel_to_il.cc
index fda2a9b..8a20c37 100644
--- a/runtime/vm/compiler/frontend/kernel_to_il.cc
+++ b/runtime/vm/compiler/frontend/kernel_to_il.cc
@@ -31,6 +31,7 @@
 #include "vm/object_store.h"
 #include "vm/report.h"
 #include "vm/resolver.h"
+#include "vm/runtime_entry.h"
 #include "vm/scopes.h"
 #include "vm/stack_frame.h"
 #include "vm/symbols.h"
@@ -407,6 +408,37 @@
   return body;
 }
 
+Fragment FlowGraphBuilder::CCall(
+    const compiler::ffi::NativeCallingConvention& native_calling_convention) {
+  Fragment body;
+
+  const intptr_t num_arguments =
+      native_calling_convention.argument_locations().length() + 1;
+  InputsArray* arguments = new (Z) InputsArray(num_arguments);
+  arguments->FillWith(nullptr, 0, num_arguments);
+  for (intptr_t i = num_arguments - 1; i >= 0; --i) {
+    (*arguments)[i] = Pop();
+  }
+  auto* const call =
+      new (Z) CCallInstr(Z, native_calling_convention, arguments);
+
+  Push(call);
+  body <<= call;
+
+  return body;
+}
+
+Fragment FlowGraphBuilder::CCall(intptr_t num_arguments,
+                                 Representation representation) {
+  const auto& native_function_type =
+      *compiler::ffi::NativeFunctionType::FromUnboxedRepresentation(
+          Z, num_arguments, representation);
+  const auto& native_calling_convention =
+      compiler::ffi::NativeCallingConvention::FromSignature(
+          Z, native_function_type);
+  return CCall(native_calling_convention);
+}
+
 Fragment FlowGraphBuilder::RethrowException(TokenPosition position,
                                             int catch_try_index) {
   Fragment instructions;
@@ -3982,9 +4014,20 @@
 }
 
 Fragment FlowGraphBuilder::EnterHandleScope() {
-  auto* instr = new (Z) EnterHandleScopeInstr();
-  Push(instr);
-  return Fragment(instr);
+  Fragment body;
+  body += LoadThread();
+  body += ConvertUntaggedToUnboxed(kUnboxedIntPtr);  // argument.
+
+  // LoadThread again, we can't store it in a temp because it will end up
+  // in the environment of the FfiCall as untagged then.
+  body += LoadThread();
+  body += LoadUntagged(compiler::target::Thread::OffsetFromThread(
+      &kEnterHandleScopeRuntimeEntry));
+  body += ConvertUntaggedToUnboxed(kUnboxedFfiIntPtr);  // function address.
+
+  body += CCall(/*num_arguments=*/1);
+
+  return body;
 }
 
 Fragment FlowGraphBuilder::GetTopHandleScope() {
@@ -3996,18 +4039,33 @@
 }
 
 Fragment FlowGraphBuilder::ExitHandleScope() {
-  auto* instr = new (Z) ExitHandleScopeInstr();
-  return Fragment(instr);
+  Fragment code;
+  code += LoadThread();
+  code += ConvertUntaggedToUnboxed(kUnboxedIntPtr);  // argument.
+
+  code += LoadThread();
+  code += LoadUntagged(compiler::target::Thread::OffsetFromThread(
+      &kExitHandleScopeRuntimeEntry));
+  code += ConvertUntaggedToUnboxed(kUnboxedFfiIntPtr);  // function address.
+
+  code += CCall(/*num_arguments=*/1);
+
+  code += Drop();
+  return code;
 }
 
 Fragment FlowGraphBuilder::AllocateHandle() {
   Fragment code;
   // Get a reference to the top handle scope.
   code += GetTopHandleScope();
-  Value* api_local_scope_value = Pop();
-  auto* instr = new (Z) AllocateHandleInstr(api_local_scope_value);
-  Push(instr);
-  code <<= instr;
+
+  code += LoadThread();
+  code += LoadUntagged(
+      compiler::target::Thread::OffsetFromThread(&kAllocateHandleRuntimeEntry));
+  code += ConvertUntaggedToUnboxed(kUnboxedFfiIntPtr);  // function address.
+
+  code += CCall(/*num_arguments=*/1);
+
   return code;
 }
 
diff --git a/runtime/vm/compiler/frontend/kernel_to_il.h b/runtime/vm/compiler/frontend/kernel_to_il.h
index 697be82..ff641cc 100644
--- a/runtime/vm/compiler/frontend/kernel_to_il.h
+++ b/runtime/vm/compiler/frontend/kernel_to_il.h
@@ -196,6 +196,11 @@
 
   Fragment FfiCall(const compiler::ffi::CallMarshaller& marshaller);
 
+  Fragment CCall(
+      const compiler::ffi::NativeCallingConvention& native_calling_convention);
+  Fragment CCall(intptr_t num_arguments,
+                 Representation representation = kUnboxedFfiIntPtr);
+
   Fragment RethrowException(TokenPosition position, int catch_try_index);
   Fragment LoadLocal(LocalVariable* variable);
   Fragment IndirectGoto(intptr_t target_count);
diff --git a/runtime/vm/runtime_entry.cc b/runtime/vm/runtime_entry.cc
index ac9d41a..a3fcc07 100644
--- a/runtime/vm/runtime_entry.cc
+++ b/runtime/vm/runtime_entry.cc
@@ -3722,7 +3722,6 @@
   return GetThreadForNativeCallback(callback_id, 0);
 }
 
-// This is called directly by EnterHandleScopeInstr.
 extern "C" ApiLocalScope* DLRT_EnterHandleScope(Thread* thread) {
   CHECK_STACK_ALIGNMENT;
   TRACE_RUNTIME_CALL("EnterHandleScope %p", thread);
@@ -3737,7 +3736,6 @@
     false /* is_float */,
     reinterpret_cast<RuntimeFunction>(&DLRT_EnterHandleScope));
 
-// This is called directly by ExitHandleScopeInstr.
 extern "C" void DLRT_ExitHandleScope(Thread* thread) {
   CHECK_STACK_ALIGNMENT;
   TRACE_RUNTIME_CALL("ExitHandleScope %p", thread);
@@ -3750,7 +3748,6 @@
     false /* is_float */,
     reinterpret_cast<RuntimeFunction>(&DLRT_ExitHandleScope));
 
-// This is called directly by AllocateHandleInstr.
 extern "C" LocalHandle* DLRT_AllocateHandle(ApiLocalScope* scope) {
   CHECK_STACK_ALIGNMENT;
   TRACE_RUNTIME_CALL("AllocateHandle %p", scope);
diff --git a/tools/VERSION b/tools/VERSION
index d5db85d..df385d9 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 18
 PATCH 0
-PRERELEASE 152
+PRERELEASE 153
 PRERELEASE_PATCH 0
\ No newline at end of file