Load the global proxy from the context of the target function.

src/hydrogen-instructions.h

 // Copyright 2012 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 2381 matching lines @@
   HCallNamed(HValue* context, Handle<String> name, int argument_count)
       : HUnaryCall(context, argument_count), name_(name) {
   }
 
   Handle<String> name_;
 };
 
 
 enum CallMode {
   NORMAL_CALL,
-  TAIL_CALL
+  TAIL_CALL,
+  NORMAL_CONTEXTUAL_CALL
 };
 
 
 class HCallFunction V8_FINAL : public HBinaryCall {
  public:
   DECLARE_INSTRUCTION_WITH_CONTEXT_FACTORY_P2(HCallFunction, HValue*, int);
   DECLARE_INSTRUCTION_WITH_CONTEXT_FACTORY_P3(
       HCallFunction, HValue*, int, CallMode);
 
   bool IsTailCall() const { return call_mode_ == TAIL_CALL; }
-
+  bool IsContextualCall() const { return call_mode_ == NORMAL_CONTEXTUAL_CALL; }
   HValue* context() { return first(); }
   HValue* function() { return second(); }
 
   DECLARE_CONCRETE_INSTRUCTION(CallFunction)
 
   virtual int argument_delta() const V8_OVERRIDE {
     if (IsTailCall()) return 0;
     return -argument_count();
   }
 
@@ skipping 5056 matching lines @@
   virtual bool IsDeletable() const V8_OVERRIDE { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_