RFR(S) 8229377: [JVMCI] Improve InstalledCode.invalidate for large code caches

[Tom Rodriguez]

http://cr.openjdk.java.net/~never/8229377/webrev
https://bugs.openjdk.java.net/browse/JDK-8229377

This is a minor improvement to the JVMCI invalidate method to avoid 
scanning large code caches when invalidating a single nmethod.  Instead 
the nmethod is directly made not_entrant.  In general I'm unclear what 
the benefit of the 
mark_for_deoptimization/make_marked_nmethods_not_entrant split is. 
Testing is in progress.

JDK-8230884 had been previously duplicated against this because they 
overlapped a bit, but in the interest of clarity I separated them again.

tom