Make invalid to override method names for local nested functions

pkg/compiler/lib/src/resolution/members.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of resolution;
 
 abstract class TreeElements {
   AnalyzableElement get analyzedElement;
   Iterable<Node> get superUses;
 
@@ skipping 2479 matching lines @@
           MessageKind.NAMED_FUNCTION_EXPRESSION,
           {'name': node.name});
     }
     visit(node.returnType);
     String name;
     if (node.name == null) {
       name = "";
     } else {
       name = node.name.asIdentifier().source;
     }
+    Modifiers modifiers = node.name == null
+        ? Modifiers.EMPTY
+        : new Modifiers.withFlags(new NodeList.empty(), Modifiers.FLAG_FINAL);
     LocalFunctionElementX function = new LocalFunctionElementX(
-        name, node, ElementKind.FUNCTION, Modifiers.EMPTY,
-        enclosingElement);
+        name, node, ElementKind.FUNCTION, modifiers, enclosingElement);

[Johnni Winther, 2015/04/10 11:49:43]

The .isFinal property means 'declaratively final' which local functions are not.

Investigating the issue I found that actually handled assignment to functions
but failed on local functions (and super functions) for obscure reasons.

I've sent you a patch you can use.

Try adding tests for assignment to local functions as well super functions (like
`super.func = 42`) to the unittest `tests/compiler/dart2js/resolver_test.dart'
to test the patch.

[Siggi Cherem (dart-lang), 2015/04/11 00:12:21]

thanks, I was not very keen of this approach, but its good to confirm - from
working with analyzer, I am used to have some element synthesize information,
for example a getter with no setter implies a synthetic final variable. 
Thanks. I've updated this CL with your patch and the extra tests

     ResolverTask.processAsyncMarker(compiler, function, registry);
     function.functionSignatureCache = SignatureResolver.analyze(
         compiler,
         node.parameters,
         node.returnType,
         function,
         registry,
         createRealParameters: true,
         isFunctionExpression: !inFunctionDeclaration);
     checkLocalDefinitionName(node, function);
@@ skipping 2564 matching lines @@
 }
 
 /// The result for the resolution of the `assert` method.
 class AssertResult implements ResolutionResult {
   const AssertResult();
 
   Element get element => null;
 
   String toString() => 'AssertResult()';
 }