Compute frontend/backend specific constants.

sdk/lib/_internal/compiler/implementation/elements/elements.dart

Index: sdk/lib/_internal/compiler/implementation/elements/elements.dart
diff --git a/sdk/lib/_internal/compiler/implementation/elements/elements.dart b/sdk/lib/_internal/compiler/implementation/elements/elements.dart
index 2e5dd423421e4c1cabac929dbe333cc4bc89d8aa..d3dd0309130229ec5021a63f112533f6c26c2fc6 100644
--- a/sdk/lib/_internal/compiler/implementation/elements/elements.dart
+++ b/sdk/lib/_internal/compiler/implementation/elements/elements.dart
@@ -1040,6 +1040,7 @@ abstract class TypeVariableElement extends Element implements TypedElement {
 }
 
 abstract class MetadataAnnotation implements Spannable {
+  /// The front-end constant of this metadata annotation.

[floitsch, 2014/04/02 16:50:02]

This feels dangerous (in the sense that I can see people use it in the backend),
but I vote for keeping it the way it is now.

[Johnni Winther, 2014/04/07 11:42:27]

Maybe rename to [frontendValue] ?

[floitsch, 2014/04/07 12:21:41]

up to you. I would LGTM both.

   Constant get value;
   Element get annotatedElement;
   int get resolutionState;
@@ -1048,7 +1049,6 @@ abstract class MetadataAnnotation implements Spannable {
 
   // TODO(kasperl): Try to get rid of these.
   void set annotatedElement(Element value);
-  void set resolutionState(int value);
 
   MetadataAnnotation ensureResolved(Compiler compiler);
 }