RFR: 8057037: Verification in ClassLoaderData::is_alive is too slow

[Stefan Karlsson]

Hi all,

Please review this patch to remove some verification code that was added 
during the G1 Class Unloading project. The code was added to make sure 
we catch any class unloading bugs as early as possible. This 
verification code is run too often and is causing large GC times in our 
fastdebug test runs. In one of the tests I investigated, the Full GCs 
take 8 seconds with this verification and 0.2 seconds without it. Most 
of the verified pointers are already verified before and after GCs in 
ClassLoaderDataGraph::verify().

http://cr.openjdk.java.net/~stefank/8057037/webrev.00/

thanks,
StefanK