Block scoped const variables.

src/full-codegen.cc

Index: src/full-codegen.cc
diff --git a/src/full-codegen.cc b/src/full-codegen.cc
index 083675d133cbfb639359bbd07b1d0b6625a133a1..69e225c1e9cae068f3ddc1ba14f03d1541b86f3e 100644
--- a/src/full-codegen.cc
+++ b/src/full-codegen.cc
@@ -520,8 +520,8 @@ void FullCodeGenerator::VisitDeclarations(
       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++);