fix ABI incompatibility problem of some JS direct-connected API

As you know, there is a issue when connect rust to c(++) between another ABIs.
So I added some glue code to use JS API normally regardless of ABI difference.

I had also modified the module : rust-mozjs
actual commit is on my local github.
https://github.com/aydinkim/rust-mozjs/commit/35c775238ef6c8e2297986b96cfaf269c9ab2782

and the source code diff is attached below.
https://gist.github.com/aydinkim/5450506