Block scoped const variables.

src/full-codegen.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 503 matching lines @@
   if (global_count > 0) {
     Handle<FixedArray> array =
         isolate()->factory()->NewFixedArray(2 * global_count, TENURED);
     for (int j = 0, i = 0; i < length; i++) {
       Declaration* decl = declarations->at(i);
       Variable* var = decl->proxy()->var();
 
       if (var->IsUnallocated()) {
         array->set(j++, *(var->name()));
         if (decl->fun() == NULL) {
-          if (var->mode() == CONST) {
-            // In case this is const property use the hole.
+          if (var->binding_needs_init()) {
+            // In case this binding needs initialization use the hole.
             array->set_the_hole(j++);
           } else {
             array->set_undefined(j++);
           }
         } else {
           Handle<SharedFunctionInfo> function =
               Compiler::BuildFunctionInfo(decl->fun(), script());
           // Check for stack-overflow exception.
           if (function.is_null()) {
             SetStackOverflow();
@@ skipping 812 matching lines @@
   }
 
   return false;
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal