Better error message for assignment to final local variables

runtime/lib/invocation_mirror.h

 // Copyright (c) 2013, 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 LIB_INVOCATION_MIRROR_H_
 #define LIB_INVOCATION_MIRROR_H_
 
 #include "vm/allocation.h"
 
 namespace dart {
 
 class InvocationMirror : public AllStatic {
  public:
   // These enum correspond to the constants in invocation_mirror_patch.dart.
   // It is used to communicate the reason for statically thrown
   // NoSuchMethodErrors by the compiler.
   enum Type {
     // Constants describing the invocation type.
     // kField cannot be generated by regular invocation mirrors.
     kMethod = 0,
     kGetter = 1,
     kSetter = 2,
     kField  = 3,
+    kLocalVar = 4,
     kTypeShift = 0,
-    kTypeBits = 2,
+    kTypeBits = 3,
     kTypeMask = (1 << kTypeBits) - 1
   };
 
   enum Call {
     // These values, except kDynamic and kSuper, are only used when throwing
     // NoSuchMethodError for compile-time resolution failures.
     kDynamic = 0,
     kSuper = 1,
     kStatic  = 2,
     kConstructor = 3,
     kTopLevel = 4,
     kCallShift = kTypeBits,
     kCallBits = 3,
     kCallMask = (1 << kCallBits) - 1
   };
 
   static int EncodeType(Call call, Type type) {
     return (call << kCallShift) | type;
   }
 };
 
 }  // namespace dart
 
 #endif  // LIB_INVOCATION_MIRROR_H_