[kernel] Move util.dart from bin to lib.

bin/util.dart doesn't have main() entry point and that breaks snapshot generation that is
automatically invoked by pub for all dart sources in bin/ folder.

See https://github.com/flutter/flutter/pull/19044\#issuecomment-402241782

Change-Id: Ie91549173536740992ce61d830efdfdc603c5564
Reviewed-on: https://dart-review.googlesource.com/63683
Commit-Queue: Alexander Aprelev <aam@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>
diff --git a/pkg/kernel/bin/count_breakdown.dart b/pkg/kernel/bin/count_breakdown.dart
index b3dbc17..fe8353f 100755
--- a/pkg/kernel/bin/count_breakdown.dart
+++ b/pkg/kernel/bin/count_breakdown.dart
@@ -5,7 +5,7 @@
 
 import 'dart:io';
 import 'package:kernel/kernel.dart';
-import 'util.dart';
+import 'package:kernel/src/tool/command_line_util.dart';
 
 void usage() {
   print("Enumerates the different node types in the provided dill file");
diff --git a/pkg/kernel/bin/dump.dart b/pkg/kernel/bin/dump.dart
index fc69f95..3d76a9a 100755
--- a/pkg/kernel/bin/dump.dart
+++ b/pkg/kernel/bin/dump.dart
@@ -6,8 +6,7 @@
 import 'dart:io';
 
 import 'package:kernel/kernel.dart';
-
-import 'util.dart';
+import 'package:kernel/src/tool/command_line_util.dart';
 
 void usage() {
   print("Prints a dill file as a textual format.");
diff --git a/pkg/kernel/bin/eval.dart b/pkg/kernel/bin/eval.dart
index 491f726..0f9ce1a 100755
--- a/pkg/kernel/bin/eval.dart
+++ b/pkg/kernel/bin/eval.dart
@@ -7,8 +7,7 @@
 
 import 'package:kernel/kernel.dart';
 import 'package:kernel/interpreter/interpreter.dart';
-
-import 'util.dart';
+import 'package:kernel/src/tool/command_line_util.dart';
 
 void usage() {
   print("Interpreter for a dill file.");
diff --git a/pkg/kernel/bin/size_breakdown.dart b/pkg/kernel/bin/size_breakdown.dart
index c2608ed..b8a5386 100755
--- a/pkg/kernel/bin/size_breakdown.dart
+++ b/pkg/kernel/bin/size_breakdown.dart
@@ -7,8 +7,7 @@
 
 import 'package:kernel/kernel.dart';
 import 'package:kernel/binary/ast_from_binary.dart';
-
-import 'util.dart';
+import 'package:kernel/src/tool/command_line_util.dart';
 
 void usage() {
   print("Gives an overview of which parts of the dill file");
diff --git a/pkg/kernel/bin/split.dart b/pkg/kernel/bin/split.dart
index 8a4df58..9bacdfc 100755
--- a/pkg/kernel/bin/split.dart
+++ b/pkg/kernel/bin/split.dart
@@ -10,8 +10,7 @@
 import 'package:kernel/binary/ast_to_binary.dart';
 import 'package:kernel/binary/limited_ast_to_binary.dart';
 import 'package:kernel/kernel.dart';
-
-import 'util.dart';
+import 'package:kernel/src/tool/command_line_util.dart';
 
 void usage() {
   print("Split a dill file into separate dill files (one library per file).");
diff --git a/pkg/kernel/bin/transform.dart b/pkg/kernel/bin/transform.dart
index ae16bda..9523e33 100755
--- a/pkg/kernel/bin/transform.dart
+++ b/pkg/kernel/bin/transform.dart
@@ -21,8 +21,7 @@
 // import 'package:kernel/verifier.dart';
 import 'package:kernel/transformations/coq.dart' as coq;
 import 'package:kernel/vm/constants_native_effects.dart';
-
-import 'util.dart';
+import 'package:kernel/src/tool/command_line_util.dart';
 
 ArgParser parser = new ArgParser()
   ..addOption('format',
diff --git a/pkg/kernel/bin/type_check.dart b/pkg/kernel/bin/type_check.dart
index e732ab6..24b78d3d 100755
--- a/pkg/kernel/bin/type_check.dart
+++ b/pkg/kernel/bin/type_check.dart
@@ -7,8 +7,7 @@
 
 import 'package:kernel/error_formatter.dart';
 import 'package:kernel/naive_type_checker.dart';
-
-import 'util.dart';
+import 'package:kernel/src/tool/command_line_util.dart';
 
 void usage() {
   print("Type checker that can be used to find strong mode");
diff --git a/pkg/kernel/bin/util.dart b/pkg/kernel/lib/src/tool/command_line_util.dart
similarity index 100%
rename from pkg/kernel/bin/util.dart
rename to pkg/kernel/lib/src/tool/command_line_util.dart