RFR 8185717: Make ModuleEntry->module() return an oop not a jobject

[Aleksey Shipilev]

On 08/07/2017 03:26 PM, harold seigel wrote:
> Open Webrev: http://cr.openjdk.java.net/~hseigel/bug_8185717/webrev/index.html

So this just moves JNIHandles::resolve calls into ModuleEntry::module(), and exposes
ModuleEntry::module_handle() in case we can do with the original (global?) handle.

This looks correct.

Thanks,
-Aleksey