Revert "Add a premonomorphic state to the call target cache."

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 29cfcb0b081533dff79447271d0ec15526fcc586..8c5a430014de2658879369f53378c2dd251dac05 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2201,25 +2201,10 @@ static void GenerateRecordCallTarget(MacroAssembler* masm) {
 
   __ bind(&miss);
 
-  // A monomorphic miss (i.e, here the cache is not uninitialized or
-  // pre-monomorphic) goes megamorphic.
-  Label not_uninitialized;
+  // A monomorphic miss (i.e, here the cache is not uninitialized) goes
+  // megamorphic.
   __ Cmp(rcx, TypeFeedbackInfo::UninitializedSentinel(isolate));
-  __ j(not_equal, &not_uninitialized);
-
-  // PremonomorphicSentinel is an immortal immovable object (null) so no
-  // write-barrier is needed.
-  __ Move(FieldOperand(rbx, rdx, times_pointer_size, FixedArray::kHeaderSize),
-          TypeFeedbackInfo::PremonomorphicSentinel(isolate));
-  __ jmp(&done);
-
-  // If the cache isn't uninitialized, it is either premonomorphic or
-  // monomorphic. If it is premonomorphic, we initialize it thus making
-  // it monomorphic. Otherwise, we go megamorphic.
-  __ bind(&not_uninitialized);
-  __ Cmp(rcx, TypeFeedbackInfo::PremonomorphicSentinel(isolate));
   __ j(equal, &initialize);
-
   // MegamorphicSentinel is an immortal immovable object (undefined) so no
   // write-barrier is needed.
   __ bind(&megamorphic);