[runtime] Port simple String.prototype.indexOf cases to TF Builtin

src/builtins/builtins-math.cc

Index: src/builtins/builtins-math.cc
diff --git a/src/builtins/builtins-math.cc b/src/builtins/builtins-math.cc
index f8bc3e194d89e85756ca60cf4728db897cae5789..31a13119a8569238d9aebd56f1ed31e9120c8da4 100644
--- a/src/builtins/builtins-math.cc
+++ b/src/builtins/builtins-math.cc
@@ -360,7 +360,7 @@ BUILTIN(MathHypot) {
   bool one_arg_is_nan = false;
   List<double> abs_values(length);
   for (int i = 0; i < length; i++) {
-    Handle<Object> x = args.at<Object>(i + 1);
+    Handle<Object> x = args.at(i + 1);
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, x, Object::ToNumber(x));
     double abs_value = std::abs(x->Number());