RFR(S): 8034860: Fatal error due to incorrect thread state during nightly testing

[Calvin Cheung]

bug: https://bugs.openjdk.java.net/browse/JDK-8034860

Please review this fix for fixing a regression caused by the fix for 
8028785.

The problem is that the env->ExpectionCheck() is being called from a vm 
thread
and triggers the following assert in trasition_from_native():

     assert(thread->thread_state() == _thread_in_native, "coming from 
wrong thread state");

A fix is to use the HAS_PENDING_EXCEPTION and CLEAR_PENDING_EXCEPTION 
macros.

Thanks to coleen.phillimore at oracle.com who suggested this fix.

webrev: http://cr.openjdk.java.net/~ccheung/8034860/webrev/

Testing:
     jtreg hotspot/test/*, java/lang/invoke (on linux_x64)
     jtreg sun/misc (on windows_x64 and linux_x64)
     jprt (in progress)

thanks,
Calvin