Summary: fix some misc things to build fastdebug version dragonwell8: fastdebug version has `-DCHECK_UNHANDLED_OOPS` which will make `oop` as an object instead of a pointer.

Test Plan: build Dragonwell in fastdebug mode

Reviewed-by: luchsh,D-D-H

Issue: https://github.com/alibaba/dragonwell8/issues/82