Reject constructor names that conflict with members.

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

Index: dart/sdk/lib/_internal/compiler/implementation/elements/elements.dart
diff --git a/dart/sdk/lib/_internal/compiler/implementation/elements/elements.dart b/dart/sdk/lib/_internal/compiler/implementation/elements/elements.dart
index d0caf293318de8c86f9a46cbc5fe3da084f58b0e..5426c727876cbb3663a4752b2ed788ca34b9c3b6 100644
--- a/dart/sdk/lib/_internal/compiler/implementation/elements/elements.dart
+++ b/dart/sdk/lib/_internal/compiler/implementation/elements/elements.dart
@@ -1857,6 +1857,16 @@ class Elements {
     return new SourceString('$r\$$s');
   }
 
+  static SourceString deconstructConstructorName(SourceString name,
+                                                 ClassElement holder) {
+    String r = '${holder.name.slowToString()}\$';
+    String s = name.slowToString();
+    if (s.startsWith(r)) {
+      return new SourceString(s.substring(r.length));
+    }
+    return null;
+  }
+
   /**
    * Map an operator-name to a valid Dart identifier.
    *