Avoid emitting addStubs and tearOffCode when not needed.

pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart

Index: pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
diff --git a/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart b/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
index 3fa2c8f1683675b33c93a84dfdf1b49a4b13622c..785d25cf106e8a9737e712b96edf001a9d5e8eef 100644
--- a/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
+++ b/pkg/compiler/lib/src/js_emitter/old_emitter/emitter.dart
@@ -24,6 +24,10 @@ class OldEmitter implements Emitter {
   bool needsClassSupport = false;
   bool needsMixinSupport = false;
   bool needsLazyInitializer = false;
+  /// This is set to true in ContainerBuilder if the program contains

[ahe, 2015/01/07 13:14:52]

Add newline before line 27 and after line 30.

[zarah, 2015/01/07 14:23:09]

Done, in another CL.

+  /// function elements that need extra handling. In this case the element is

[ahe, 2015/01/07 13:14:52]

This is a rather long comment, but it actually doesn't contain much information.

The part "extra handling" is vague, but also what is interesting.

I'd suggest:

/// True if [ContainerBuilder.addMemberMethodFromInfo] used "structured info",
that is, some function was needed for reflection, had stubs, or had a super
alias.

This uses the same wording and terminology as used in
ContainerBuilder.addMemberMethodFromInfo.

[zarah, 2015/01/07 14:23:09]

Done, in another CL.

+  /// stored along with an array containing the needed information.
+  bool needsArrayInitializerSupport = false;
   final Namer namer;
   ConstantEmitter constantEmitter;
   NativeEmitter get nativeEmitter => task.nativeEmitter;