Stack allocating block scoped variables.

src/scopes.h

Index: src/scopes.h
diff --git a/src/scopes.h b/src/scopes.h
index 523a251fae2ffd18f5bb1148a2c17b575b6faf8b..ee0652ff34dae53b3101340e5c8dde2507a99bab 100644
--- a/src/scopes.h
+++ b/src/scopes.h
@@ -339,6 +339,16 @@ class Scope: public ZoneObject {
   int StackLocalCount() const;
   int ContextLocalCount() const;
 
+  // Computed during code generation; for block scopes only. The depth
+  // above the function locals on the stack at which the stack locals
+  // of the block start.
+  int stack_slots_depth() const {
+    return stack_slots_depth_;
+  }
+  void set_stack_slots_depth(int stack_slots_depth) {
+    stack_slots_depth_ = stack_slots_depth;
+  }
+
   // Make sure this scope and all outer scopes are eagerly compiled.
   void ForceEagerCompilation()  { force_eager_compilation_ = true; }
 
@@ -456,6 +466,9 @@ class Scope: public ZoneObject {
   int num_stack_slots_;
   int num_heap_slots_;
 
+  // Computed during code generation; for block scopes only.
+  int stack_slots_depth_;
+
   // Serialized scope info support.
   Handle<ScopeInfo> scope_info_;
   bool already_resolved() { return already_resolved_; }