Refactor resolution code in the vm to properly handle ambiguity errors.

runtime/vm/resolver.h

 // Copyright (c) 2011, 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.
 
 #ifndef VM_RESOLVER_H_
 #define VM_RESOLVER_H_
 
 #include "vm/allocation.h"
 
 namespace dart {
@@ skipping 35 matching lines @@
   // either application library or core library if no application library
   // exists. Passing negative num_arguments means that the function
   // will be resolved by name only.
   // Otherwise null is returned if the number or names of arguments are not
   // valid for the resolved function.
   static RawFunction* ResolveStatic(const Library& library,
                                     const String& cls_name,
                                     const String& function_name,
                                     intptr_t num_arguments,
                                     const Array& argument_names,
-                                    StaticResolveType resolve_type);
+                                    StaticResolveType resolve_type,
+                                    String* ambiguity_error_msg);
 
   // Resolve specified dart static function.
   static RawFunction* ResolveStaticByName(const Class&  cls,
                                           const String& function_name,
                                           StaticResolveType resolve_type);
 
   // Resolve specified dart static function with specified arity.
   static RawFunction* ResolveStatic(const Class&  cls,
                                     const String& function_name,
                                     intptr_t num_arguments,
                                     const Array& argument_names,
                                     StaticResolveType resolve_type);
 };
 
 }  // namespace dart
 
 #endif  // VM_RESOLVER_H_