7051430: CMS: ongoing CMS cycle should terminate abruptly to allow prompt JVM termination at exit Summary: It turns out that there is no need to explicitly stop CMS since the JVM is taken down at a terminal safepoint during which CMS threads are (terminally) inactive. This will need to be revised if and when we evolve in the future to a point where we allow JVM reincarnation in the same process, but those changes will be much more sweeping than just terminating CMS threads. The unused ::stop() methods will be removed in a separate CR. Also include in this CR is the fix for a small typo in the spelling of UseGCLogFileRotation in a message in arguments.cpp, brought to our attention by Rainer Jung and reviewed by minqi. Reviewed-by: johnc, jwilhelm