Make closures optimizable by Crankshaft compiler.

src/variables.cc

 // Copyright 2006-2008 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 80 matching lines @@
   return s != NULL && s->type() == Slot::PARAMETER;
 }
 
 
 bool Variable::IsStackLocal() const {
   Slot* s = AsSlot();
   return s != NULL && s->type() == Slot::LOCAL;
 }
 
 
+bool Variable::IsContextSlot() const {
+  Slot* s = AsSlot();
+  return s != NULL && s->type() == Slot::CONTEXT;
+}
+
+
 Variable::Variable(Scope* scope,
                    Handle<String> name,
                    Mode mode,
                    bool is_valid_LHS,
                    Kind kind)
   : scope_(scope),
     name_(name),
     mode_(mode),
     is_valid_LHS_(is_valid_LHS),
     kind_(kind),
     local_if_not_shadowed_(NULL),
     is_accessed_from_inner_scope_(false),
     is_used_(false),
     rewrite_(NULL) {
   // names must be canonicalized for fast equality checks
   ASSERT(name->IsSymbol());
 }
 
 
 bool Variable::is_global() const {
   // Temporaries are never global, they must always be allocated in the
   // activation frame.
   return mode_ != TEMPORARY && scope_ != NULL && scope_->is_global_scope();
 }
 
 } }  // namespace v8::internal