Fix for class members cannot have the same name as the class in dart2js

lib/compiler/implementation/resolver.dart

Index: lib/compiler/implementation/resolver.dart
diff --git a/lib/compiler/implementation/resolver.dart b/lib/compiler/implementation/resolver.dart
index 132050d262edc7db89d26cdf70847d240fa79aab..e41662f7bdab33d5856740a07a0e59e62de8fbee 100644
--- a/lib/compiler/implementation/resolver.dart
+++ b/lib/compiler/implementation/resolver.dart
@@ -119,6 +119,9 @@ class ResolverTask extends CompilerTask {
       }
       FunctionExpression tree = element.parseNode(compiler);
       if (isConstructor) {
+        if (tree.returnType != null) {
+          error(tree, MessageKind.CONSTRUCTOR_WITH_RETURN_TYPE);
+        }
         resolveConstructorImplementation(element, tree);
       }
       ResolverVisitor visitor = new ResolverVisitor(compiler, element);