[compiler] Drop the CompareNilIC.

src/ic/ic.cc

Index: src/ic/ic.cc
diff --git a/src/ic/ic.cc b/src/ic/ic.cc
index 4c2b20ca1b84b9b9de0ef79c741e9cb939328797..c7ab8cec048b250459fc9c571a4119640a5c2c05 100644
--- a/src/ic/ic.cc
+++ b/src/ic/ic.cc
@@ -465,8 +465,6 @@ void IC::Clear(Isolate* isolate, Address address, Address constant_pool) {
       return;
     case Code::COMPARE_IC:
       return CompareIC::Clear(isolate, address, target, constant_pool);
-    case Code::COMPARE_NIL_IC:
-      return CompareNilIC::Clear(address, target, constant_pool);
     case Code::CALL_IC:  // CallICs are vector-based and cleared differently.
     case Code::BINARY_OP_IC:
     case Code::TO_BOOLEAN_IC:
@@ -2714,57 +2712,6 @@ RUNTIME_FUNCTION(Runtime_CompareIC_Miss) {
 }
 
 
-void CompareNilIC::Clear(Address address, Code* target, Address constant_pool) {
-  if (IsCleared(target)) return;
-  ExtraICState state = target->extra_ic_state();
-
-  CompareNilICStub stub(target->GetIsolate(), state,
-                        HydrogenCodeStub::UNINITIALIZED);
-  stub.ClearState();
-
-  Code* code = NULL;
-  CHECK(stub.FindCodeInCache(&code));
-
-  SetTargetAtAddress(address, code, constant_pool);
-}
-
-
-Handle<Object> CompareNilIC::CompareNil(Handle<Object> object) {
-  ExtraICState extra_ic_state = target()->extra_ic_state();
-
-  CompareNilICStub stub(isolate(), extra_ic_state);
-
-  // Extract the current supported types from the patched IC and calculate what
-  // types must be supported as a result of the miss.
-  bool already_monomorphic = stub.IsMonomorphic();
-
-  stub.UpdateStatus(object);
-
-  // Find or create the specialized stub to support the new set of types.
-  Handle<Code> code;
-  if (stub.IsMonomorphic()) {
-    Handle<Map> monomorphic_map(already_monomorphic && FirstTargetMap() != NULL
-                                    ? FirstTargetMap()
-                                    : HeapObject::cast(*object)->map());
-    code = PropertyICCompiler::ComputeCompareNil(monomorphic_map, &stub);
-  } else {
-    code = stub.GetCode();
-  }
-  set_target(*code);
-  return isolate()->factory()->ToBoolean(object->IsUndetectableObject());
-}
-
-
-RUNTIME_FUNCTION(Runtime_CompareNilIC_Miss) {
-  TimerEventScope<TimerEventIcMiss> timer(isolate);
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8"), "V8.IcMiss");
-  HandleScope scope(isolate);
-  Handle<Object> object = args.at<Object>(0);
-  CompareNilIC ic(isolate);
-  return *ic.CompareNil(object);
-}
-
-
 RUNTIME_FUNCTION(Runtime_Unreachable) {
   UNREACHABLE();
   CHECK(false);