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

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
diff --git a/src/x64/lithium-codegen-x64.cc b/src/x64/lithium-codegen-x64.cc
index c392b455d55a5f69b9959a22b8081c904eb2e123..917d1e2580812ad61f443a598763919310213b7e 100644
--- a/src/x64/lithium-codegen-x64.cc
+++ b/src/x64/lithium-codegen-x64.cc
@@ -3236,10 +3236,7 @@ void LCodeGen::DoWrapReceiver(LWrapReceiver* instr) {
   // TODO(kmillikin): We have a hydrogen value for the global object.  See
   // if it's better to use it than to explicitly fetch it from the context
   // here.
-  __ movq(receiver, Operand(rbp, StandardFrameConstants::kContextOffset));
-  __ movq(receiver, ContextOperand(receiver, Context::GLOBAL_OBJECT_INDEX));
-  __ movq(receiver,
-          FieldOperand(receiver, JSGlobalObject::kGlobalReceiverOffset));
+  CallStubCompiler::FetchGlobalProxy(masm(), receiver, function);
   __ bind(&receiver_ok);
 }
 
@@ -3804,7 +3801,10 @@ void LCodeGen::DoCallFunction(LCallFunction* instr) {
   ASSERT(ToRegister(instr->result()).is(rax));
 
   int arity = instr->arity();
-  CallFunctionStub stub(arity, NO_CALL_FUNCTION_FLAGS);
+  CallFunctionFlags flags =
+      instr->hydrogen()->IsContextualCall() ?
+          RECEIVER_IS_IMPLICIT : NO_CALL_FUNCTION_FLAGS;
+  CallFunctionStub stub(arity, flags);
   if (instr->hydrogen()->IsTailCall()) {
     if (NeedsEagerFrame()) __ leave();
     __ jmp(stub.GetCode(isolate()), RelocInfo::CODE_TARGET);