RFR 8209443: [lworld] byteMutation test asserts intermittently in the verifier

[Harold David Seigel]

Hi,

Please review this LWorld change for bug JDK-8209443.  The fix checks 
that the verificationType is not an uninitialized type before calling 
VerificationType.name(), preventing VerificationType::name() from 
asserting.  The fix also includes two small changes to use the constant 
pool index version of is_declared_value_type(), instead of the class 
name version.

Open Webrev: http://cr.openjdk.java.net/~hseigel/bug_8209443/webrev/

JBS Bug:  https://bugs.openjdk.java.net/browse/JDK-8209443

The changes were tested with Mach5 tiers 1 - 5 on Linux and Mac. 
Additionally, the byteMutation test was run over 25 times against the fix.

Thanks, Harold