RFR (XS) 8059595: Verifier::verify is wasting time before is_eligible_for_verification check

[Aleksey Shipilev]

Hi,

Please review a tiny performance improvement in Verifier:
  http://cr.openjdk.java.net/~shade/8059595/webrev.00/
  https://bugs.openjdk.java.net/browse/JDK-8059595

The minuscule performance problem is that we check for verification
eligibility after doing a heavy-lifting for klass->external_name() and
such. The solution is to move the local initialization after the
eligibility check. That involves moving the PENDING_EXCEPTION checking
block under the eligibility check, since the locals are used there.
After you do that, it seems prudent to just invert the branch for the
same effect.

Anyone savvy with Verifier code (Harold?) can confirm this is safe change?

Testing: JPRT, targeted performance test on Linux x86_64/fastdebug.

Thanks,
-Aleksey.