Stack allocating block scoped variables.

src/scopes.cc

Index: src/scopes.cc
diff --git a/src/scopes.cc b/src/scopes.cc
index e05ca172518cdf8cdc7abf4eb9ef697673bd1c9e..9092499ee907b0f006d4ccf31e965c5684343674 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -148,6 +148,7 @@ Scope::Scope(Scope* inner_scope,
   SetDefaults(type, NULL, scope_info);
   if (!scope_info.is_null()) {
     num_heap_slots_ = scope_info_->ContextLength();
+    stack_slots_depth_ = scope_info_->StackSlotsDepth();
     if (*scope_info != ScopeInfo::Empty()) {
       language_mode_ = scope_info->language_mode();
     }
@@ -207,6 +208,7 @@ void Scope::SetDefaults(ScopeType type,
   scope_info_ = scope_info;
   start_position_ = RelocInfo::kNoPosition;
   end_position_ = RelocInfo::kNoPosition;
+  stack_slots_depth_ = 0;
   if (!scope_info.is_null()) {
     scope_calls_eval_ = scope_info->CallsEval();
     language_mode_ = scope_info->language_mode();
@@ -1007,8 +1009,7 @@ bool Scope::MustAllocate(Variable* var) {
        scope_calls_eval_ ||
        inner_scope_calls_eval_ ||
        scope_contains_with_ ||
-       is_catch_scope() ||
-       is_block_scope())) {
+       is_catch_scope())) {
     var->set_is_used(true);
   }
   // Global variables do not need to be allocated.
@@ -1025,7 +1026,7 @@ bool Scope::MustAllocateInContext(Variable* var) {
   // Exceptions: temporary variables are never allocated in a context;
   // catch-bound variables are always allocated in a context.
   if (var->mode() == TEMPORARY) return false;
-  if (is_catch_scope() || is_block_scope()) return true;
+  if (is_catch_scope()) return true;
   return var->has_forced_context_allocation() ||
       scope_calls_eval_ ||
       inner_scope_calls_eval_ ||