Cleanup THREAD/TRAPS/CHECK usage in JRT_ENTRY routines

All JRT_ENTRY routines are required to have a parameter, "JavaThread* thread", which must be the current thread. The JRT_ENTRY, and related macros, then use this parameter and also expose it as THREAD for use with exception macros. But the fact "thread" is the current thread is lost in some routines and we see strange calls to other code that pass both "thread" and "THREAD" as distinct parameters - primarily when a TRAPS method is involved.

This should be cleaned up along with a general check on misuse of TRAPS.

Ideally I'd also change "thread" to "current" but that may be a little too disruptive