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

src/elements.cc

Index: src/elements.cc
diff --git a/src/elements.cc b/src/elements.cc
index ffea033c93967fad28e66005bc3d62d7ceddad6f..32581bd8aead1505a830ce60ba525b8728862ca5 100644
--- a/src/elements.cc
+++ b/src/elements.cc
@@ -3699,9 +3699,9 @@ MaybeHandle<Object> ArrayConstructInitializeElements(Handle<JSArray> array,
     JSArray::Initialize(array, JSArray::kPreallocatedArrayElements);
     return array;
 
-  } else if (args->length() == 1 && args->at<Object>(0)->IsNumber()) {
+  } else if (args->length() == 1 && args->at(0)->IsNumber()) {
     uint32_t length;
-    if (!args->at<Object>(0)->ToArrayLength(&length)) {
+    if (!args->at(0)->ToArrayLength(&length)) {
       return ThrowArrayLengthRangeError(array->GetIsolate());
     }