RFR: 8140584: nmethod::oops_do_marking_epilogue always runs verification code

[Stefan Karlsson]

Hi,

Please review this patch to remove some unnecessary verification code 
from our product builds.

Today, CodeCache::gc_epilogue() guards the call to 
nmethod::verify_oop_relocations with DEBUG_ONLY, while 
nmethod::oops_do_marking_epilogue doesn't. Since 
nmethod::verify_oop_relocations uses asserts when verifying the 
relocations, this is just wasted cycles in product builds. This patch 
adds DEBUG_ONLY to nmethod::oops_do_marking_epilogue.

http://cr.openjdk.java.net/~stefank/8140584/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8140584

Thanks,
StefanK