Improve performance of export resolving / module loading

In games like God Eater Burst and etc. which use a lot of exports, there were noticeable lags while the linking happened.

This optimizes those functions so the delay is gone.  These two functions were eating about 0.7s all by themselves during a single scene switch in God Eater Burst on my hardware.

I don't have it, but I would expect this to fix #2602 since I think it also loads modules like this.

-[Unknown]