RFR (S): 8236844: Deprecate PrintVMQWaitTime to prepare for its removal

[David Holmes]

bug: https://bugs.openjdk.java.net/browse/JDK-8236844
CSR request: https://bugs.openjdk.java.net/browse/JDK-8238584
webrev: http://cr.openjdk.java.net/~dholmes/8236844/webrev/

I originally considered converting PrintVMQWaitTime to Unified Logging, 
but after some discussions and considering that proper logging of the VM 
operations involves a lot more than this one existing print statement, 
it was decided just to deprecate and then remove this flag (and the one 
print statement). There is other work in the safepoint/VM-ops area that 
will address appropriate logging as needed.

I also need reviewers for the CSR request please (first one needs to 
Edit the CSR request so that the 'Reviewers' field then appears).

Thanks,
David