Add runtimeType() to Object which returns canonicalized instances of Type.

lib/compiler/implementation/compiler.dart

Index: lib/compiler/implementation/compiler.dart
diff --git a/lib/compiler/implementation/compiler.dart b/lib/compiler/implementation/compiler.dart
index b91a4580dcfdaec308f3f10c6980fbb122ab913e..45b8ebbe157fd57b3244925f1cf94135e12943eb 100644
--- a/lib/compiler/implementation/compiler.dart
+++ b/lib/compiler/implementation/compiler.dart
@@ -164,9 +164,11 @@ class Compiler implements DiagnosticListener {
   static const SourceString MAIN = const SourceString('main');
   static const SourceString CALL_OPERATOR_NAME = const SourceString('call');
   static const SourceString NO_SUCH_METHOD = const SourceString('noSuchMethod');
+  static const SourceString RUNTIME_TYPE = const SourceString('runtimeType');
   static const SourceString START_ROOT_ISOLATE =
       const SourceString('startRootIsolate');
   bool enabledNoSuchMethod = false;
+  bool enabledRuntimeType = false;
 
   Stopwatch progress;