Revert of [compiler] Drop the CompareNilIC.

src/code-stubs-hydrogen.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stubs.h"
 
 #include "src/bailout-reason.h"
 #include "src/crankshaft/hydrogen.h"
 #include "src/crankshaft/lithium.h"
 #include "src/field-index.h"
@@ skipping 1401 matching lines @@
   return BuildInternalArrayConstructor(kind, MULTIPLE);
 }
 
 
 Handle<Code> InternalArrayNArgumentsConstructorStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 template <>
+HValue* CodeStubGraphBuilder<CompareNilICStub>::BuildCodeInitializedStub() {
+  Isolate* isolate = graph()->isolate();
+  CompareNilICStub* stub = casted_stub();
+  HIfContinuation continuation;
+  Handle<Map> sentinel_map(isolate->heap()->meta_map());
+  Type* type = stub->GetType(zone(), sentinel_map);
+  BuildCompareNil(GetParameter(0), type, &continuation, kEmbedMapsViaWeakCells);
+  IfBuilder if_nil(this, &continuation);
+  if_nil.Then();
+  if (continuation.IsFalseReachable()) {
+    if_nil.Else();
+    if_nil.Return(graph()->GetConstantFalse());
+  }
+  if_nil.End();
+  return continuation.IsTrueReachable() ? graph()->GetConstantTrue()
+                                        : graph()->GetConstantUndefined();
+}
+
+
+Handle<Code> CompareNilICStub::GenerateCode() {
+  return DoGenerateCode(this);
+}
+
+
+template <>
 HValue* CodeStubGraphBuilder<BinaryOpICStub>::BuildCodeInitializedStub() {
   BinaryOpICState state = casted_stub()->state();
 
   HValue* left = GetParameter(BinaryOpICStub::kLeft);
   HValue* right = GetParameter(BinaryOpICStub::kRight);
 
   Type* left_type = state.GetLeftType();
   Type* right_type = state.GetRightType();
   Type* result_type = state.GetResultType();
 
@@ skipping 967 matching lines @@
   return Pop();
 }
 
 
 Handle<Code> KeyedLoadGenericStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 }  // namespace internal
 }  // namespace v8