Rewrite how we handle synthesized constructors in the compiler. This was motivated by issue https:/…

sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart	(revision 25107)
+++ sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart	(working copy)
@@ -3417,7 +3417,7 @@
     if (!backend.retainMetadataOf(element)) return code;
     return compiler.withCurrentElement(element, () {
       List<int> metadata = <int>[];
-      FunctionSignature signature = element.functionSignature;
+      FunctionSignature signature = element.computeSignature(compiler);

[ahe, 2013/07/18 09:59:32]

Why this change?

[ngeoffray, 2013/07/18 15:25:14]

Apparently, it's not ensured that functionSignature is not null at this point.

[ahe, 2013/07/19 09:10:44]

That is a bug.  It must be non-null. Calling computeSignature can start
enqueueing stuff.

I think it would be best if you can ensure the resolver has computed the
signature already.

[ngeoffray, 2013/08/15 08:23:19]

Done in: https://codereview.chromium.org/22874003/

       if (element.isConstructor()) {
         metadata.add(reifyType(element.getEnclosingClass().thisType));
       } else {