[stubs] Unify (and optimize) implementation of ToObject.

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 fb46633f0b3c961f20931053ea2a26d24263e885..4afd592ab19a4837451eb41dc6b6302e84cad1b0 100644
--- a/src/code-stubs-hydrogen.cc
+++ b/src/code-stubs-hydrogen.cc
@@ -1657,6 +1657,16 @@ Handle<Code> ElementsTransitionAndStoreStub::GenerateCode() {
 }
 
 
+template <>
+HValue* CodeStubGraphBuilder<ToObjectStub>::BuildCodeStub() {
+  HValue* receiver = GetParameter(ToObjectDescriptor::kReceiverIndex);
+  return BuildToObject(receiver);
+}
+
+
+Handle<Code> ToObjectStub::GenerateCode() { return DoGenerateCode(this); }
+
+
 void CodeStubGraphBuilderBase::BuildCheckAndInstallOptimizedCode(
     HValue* js_function,
     HValue* native_context,