Drop null/undefined check if we already check for IsUndetectable in BuildCompareNil

src/ic/ic.cc

Index: src/ic/ic.cc
diff --git a/src/ic/ic.cc b/src/ic/ic.cc
index 0f1d4cce1c9c326b9ba775ec4028ddc6d443d48f..05a6dd7dbd1794d0be447edb0e82f26f26fd9d54 100644
--- a/src/ic/ic.cc
+++ b/src/ic/ic.cc
@@ -2738,15 +2738,6 @@ void CompareNilIC::Clear(Address address, Code* target, Address constant_pool) {
 }
 
 
-Handle<Object> CompareNilIC::DoCompareNilSlow(Isolate* isolate, NilValue nil,
-                                              Handle<Object> object) {
-  if (object->IsNull() || object->IsUndefined()) {
-    return isolate->factory()->true_value();
-  }
-  return isolate->factory()->ToBoolean(object->IsUndetectableObject());
-}
-
-
 Handle<Object> CompareNilIC::CompareNil(Handle<Object> object) {
   ExtraICState extra_ic_state = target()->extra_ic_state();
 
@@ -2758,8 +2749,6 @@ Handle<Object> CompareNilIC::CompareNil(Handle<Object> object) {
 
   stub.UpdateStatus(object);
 
-  NilValue nil = stub.nil_value();
-
   // Find or create the specialized stub to support the new set of types.
   Handle<Code> code;
   if (stub.IsMonomorphic()) {
@@ -2771,7 +2760,7 @@ Handle<Object> CompareNilIC::CompareNil(Handle<Object> object) {
     code = stub.GetCode();
   }
   set_target(*code);
-  return DoCompareNilSlow(isolate(), nil, object);
+  return isolate()->factory()->ToBoolean(object->IsUndetectableObject());
 }