[dart2js] Use '...' now that bug 37302 is fixed

Change-Id: I83a8b189fcfbcbdd5ecfa2a894b52336a2779a9c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/107161
Reviewed-by: Mayank Patke <fishythefish@google.com>
Commit-Queue: Stephen Adams <sra@google.com>
diff --git a/pkg/compiler/lib/src/js_backend/namer_names.dart b/pkg/compiler/lib/src/js_backend/namer_names.dart
index 61d721a..dd8c765 100644
--- a/pkg/compiler/lib/src/js_backend/namer_names.dart
+++ b/pkg/compiler/lib/src/js_backend/namer_names.dart
@@ -140,13 +140,7 @@
 
   CompoundName(this._parts);
 
-  // TODO(37302): Use
-  // CompoundName.from(List<jsAst.Name> parts) : this(<_NamerName>[...parts]);
-  CompoundName.from(List<jsAst.Name> parts) : _parts = [] {
-    for (var part in parts) {
-      _parts.add(part);
-    }
-  }
+  CompoundName.from(List<jsAst.Name> parts) : this(<_NamerName>[...parts]);
 
   @override
   String get name {
diff --git a/pkg/compiler/lib/src/js_backend/runtime_types_new.dart b/pkg/compiler/lib/src/js_backend/runtime_types_new.dart
index b75b178..4135d60 100644
--- a/pkg/compiler/lib/src/js_backend/runtime_types_new.dart
+++ b/pkg/compiler/lib/src/js_backend/runtime_types_new.dart
@@ -98,10 +98,7 @@
     }
     _flushCodes();
     jsAst.LiteralString quote = jsAst.LiteralString('"');
-    // TODO(37302): Use [quote, ..._fragments, quote].
-    return jsAst.StringConcatenation(<jsAst.Literal>[quote]
-      ..addAll(_fragments)
-      ..add(quote));
+    return jsAst.StringConcatenation([quote, ..._fragments, quote]);
   }
 
   void _start(TypeRecipe recipe) {