vector-based ICs did not update type feedback counts correctly.

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 7d1e4f5e0d0f9d416c682b47ec680599acdfb7e1..a95ddf0a89e90995ee0a6eba9e2f4670462e1efb 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2109,17 +2109,6 @@ void CallICStub::Generate(MacroAssembler* masm) {
   __ Cmp(rcx, TypeFeedbackVector::UninitializedSentinel(isolate));
   __ j(equal, &miss);
 
-  if (!FLAG_trace_ic) {
-    // We are going megamorphic. If the feedback is a JSFunction, it is fine
-    // to handle it here. More complex cases are dealt with in the runtime.
-    __ AssertNotSmi(rcx);
-    __ CmpObjectType(rcx, JS_FUNCTION_TYPE, rcx);
-    __ j(not_equal, &miss);
-    __ Move(FieldOperand(rbx, rdx, times_pointer_size, FixedArray::kHeaderSize),
-            TypeFeedbackVector::MegamorphicSentinel(isolate));
-    __ jmp(&slow_start);
-  }
-
   // We are here because tracing is on or we are going monomorphic.
   __ bind(&miss);
   GenerateMiss(masm);