RFR (S) 8074355: make MutexLocker smarter about non-JavaThreads

[coleen.phillimore at oracle.com]

Summary: Use safepoint_check_always/safepoint_check_never instead of 
safepoint_check_sometimes for locks that are taken by JavaThreads and 
non-JavaThreads

This patch moves all but 3 of the locks to not be 
safepoint_check_sometimes.  We have plans to fix these three.  Also, 
this patch allows for being explicit about safepoint checking or not 
when the thread is a non-java thread, which is something that Kim 
objected to in my first patch.

Tested with mach5 tier1-3.

open webrev at http://cr.openjdk.java.net/~coleenp/2019/8074355.03/webrev
bug link https://bugs.openjdk.java.net/browse/JDK-8074355

Thanks,
Coleen