8028126: nsk/jvmti/scenarios/hotswap/HS101/hs101t006 Crashed the vm on Solaris-sparc64 fastdebug builds: only current thread can flush its registers
Summary: Fix a race between VMOp_GetCurrentLocation reaching a safepoint and arget thread exiting from Java execution
Reviewed-by: sla, dholmes, dsamersoff
Contributed-by: serguei.spitsyn@oracle.com