RFR(S): 8186437: Lock held when compiler thread creation is aborted.

[Lindenmaier, Goetz]

Hi,

Could I please get reviews for this small change? I also please need a sponsor.
http://cr.openjdk.java.net/~goetz/wr17/8186437-compThrLock/

When the VM is aborted because compiler thread creation fails (seen in 
TestOprionsWithRanges with huge stack size) the Thread_lock was not 
released.

Best regards,
  Goetz.