Add an IC for CompareNil operations

src/code-stubs-hydrogen.cc

Index: src/code-stubs-hydrogen.cc
diff --git a/src/code-stubs-hydrogen.cc b/src/code-stubs-hydrogen.cc
index f8661566e041714a46ea5543405dca69507a4e66..7edbee7efe298baf6364a759c7a39440fa495f6f 100644
--- a/src/code-stubs-hydrogen.cc
+++ b/src/code-stubs-hydrogen.cc
@@ -509,4 +509,31 @@ Handle<Code> ArrayNArgumentsConstructorStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
+
+template <>
+HValue* CodeStubGraphBuilder<CompareNilICStub>::BuildCodeUninitializedStub() {
+  CompareNilICStub* stub = casted_stub();
+  HIfContinuation continuation;
+  Handle<Map> sentinel_map(graph()->isolate()->heap()->meta_map());
+  BuildCompareNil(GetParameter(2), stub->Kind(),
+                  stub->GetTypes(), sentinel_map,
+                  RelocInfo::kNoPosition, &continuation);
+  IfBuilder if_nil(this, &continuation);
+  if_nil.Then();
+  if (continuation.IsTrueReachable()) {
+    environment()->Push(graph()->GetConstantSmi1());
+  }
+  if (continuation.IsFalseReachable()) {
+    if_nil.Else();
+    environment()->Push(graph()->GetConstantSmi0());
+  }
+  if_nil.End();
+  return environment()->Pop();
+}
+
+
+Handle<Code> CompareNilICStub::GenerateCode() {
+  return DoGenerateCode(this);
+}
+
 } }  // namespace v8::internal