Revert of Replace all remaining Oddball checks with new function

src/runtime/runtime-forin.cc

Index: src/runtime/runtime-forin.cc
diff --git a/src/runtime/runtime-forin.cc b/src/runtime/runtime-forin.cc
index e57016a6d39c847d2ea51bfc9630fc772cdd9f32..421b395e5db7e52af787e24e1151f65a84608285 100644
--- a/src/runtime/runtime-forin.cc
+++ b/src/runtime/runtime-forin.cc
@@ -65,7 +65,7 @@
           Handle<Object> prototype;
           ASSIGN_RETURN_ON_EXCEPTION(isolate, prototype,
                                      JSProxy::GetPrototype(proxy), Object);
-          if (prototype->IsNull(isolate)) break;
+          if (prototype->IsNull()) break;
           // We already have a stack-check in JSProxy::GetPrototype.
           return HasEnumerableProperty(
               isolate, Handle<JSReceiver>::cast(prototype), key);