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

src/full-codegen/arm64/full-codegen-arm64.cc

Index: src/full-codegen/arm64/full-codegen-arm64.cc
diff --git a/src/full-codegen/arm64/full-codegen-arm64.cc b/src/full-codegen/arm64/full-codegen-arm64.cc
index 1465731ec43af1ddc747a83c20f4bb999b33ef07..412e1f5c6ce4ef49e9d5b8bf515a139b760ee2b4 100644
--- a/src/full-codegen/arm64/full-codegen-arm64.cc
+++ b/src/full-codegen/arm64/full-codegen-arm64.cc
@@ -1085,8 +1085,8 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
   __ JumpIfSmi(x0, &convert);
   __ JumpIfObjectType(x0, x10, x11, FIRST_SPEC_OBJECT_TYPE, &done_convert, ge);
   __ Bind(&convert);
-  __ Push(x0);
-  __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+  ToObjectStub stub(isolate());
+  __ CallStub(&stub);
   __ Bind(&done_convert);
   PrepareForBailoutForId(stmt->ToObjectId(), TOS_REG);
   __ Push(x0);
@@ -3726,6 +3726,19 @@ void FullCodeGenerator::EmitNumberToString(CallRuntime* expr) {
 }
 
 
+void FullCodeGenerator::EmitToObject(CallRuntime* expr) {
+  ZoneList<Expression*>* args = expr->arguments();
+  DCHECK_EQ(1, args->length());
+
+  // Load the argument into x0 and convert it.
+  VisitForAccumulatorValue(args->at(0));
+
+  ToObjectStub stub(isolate());
+  __ CallStub(&stub);
+  context()->Plug(x0);
+}
+
+
 void FullCodeGenerator::EmitStringCharFromCode(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);