X87: Built-in apply() performance benefits from an uninitialized IC.

src/x87/builtins-x87.cc

Index: src/x87/builtins-x87.cc
diff --git a/src/x87/builtins-x87.cc b/src/x87/builtins-x87.cc
index 2fa599b6d050e68c909190b1bdd0b230b2f80374..311290ff2f96a7e10f266458fbb6b696b324d942 100644
--- a/src/x87/builtins-x87.cc
+++ b/src/x87/builtins-x87.cc
@@ -1052,13 +1052,21 @@ static void Generate_PushAppliedArguments(MacroAssembler* masm,
   Label entry, loop;
   Register receiver = LoadDescriptor::ReceiverRegister();
   Register key = LoadDescriptor::NameRegister();
+  Register slot = LoadDescriptor::SlotRegister();
+  Register vector = LoadWithVectorDescriptor::VectorRegister();
   __ mov(key, Operand(ebp, indexOffset));
   __ jmp(&entry);
   __ bind(&loop);
   __ mov(receiver, Operand(ebp, argumentsOffset));  // load arguments
 
   // Use inline caching to speed up access to arguments.
-  Handle<Code> ic = masm->isolate()->builtins()->KeyedLoadIC_Megamorphic();
+  FeedbackVectorSpec spec(0, Code::KEYED_LOAD_IC);
+  Handle<TypeFeedbackVector> feedback_vector =
+      masm->isolate()->factory()->NewTypeFeedbackVector(&spec);
+  int index = feedback_vector->GetIndex(FeedbackVectorICSlot(0));
+  __ mov(slot, Immediate(Smi::FromInt(index)));
+  __ mov(vector, Immediate(feedback_vector));
+  Handle<Code> ic = KeyedLoadICStub(masm->isolate()).GetCode();
   __ call(ic, RelocInfo::CODE_TARGET);
   // It is important that we do not have a test instruction after the
   // call.  A test instruction after the call is used to indicate that