RFR(S) : 8243432 : use reproducible random in :vmTestbase_vm_defmeth

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev/8243432/webrev.00
> 22 lines changed: 3 ins; 12 del; 7 mod;

Hi all,

could you please review this small patch?
from JBS: 
> this subtask is to use j.t.l.Utils.getRandomInstance() as a random number generator, where applicable, in : vmTestbase_vm_defmeth test group and marking the tests which make use of "randomness" with a proper k/w.

testing: : vmTestbase_vm_defmeth test group
JBS: https://bugs.openjdk.java.net/browse/JDK-8243432
webrevs:
- code changes: http://cr.openjdk.java.net/~iignatyev//8243432/webrev.00.code
> 16 lines changed: 1 ins; 12 del; 3 mod; 
- adding k/w: http://cr.openjdk.java.net/~iignatyev//8243432/webrev.00.kw
> 2 lines changed: 2 ins; 0 del; 0 mod; 
- full: http://cr.openjdk.java.net/~iignatyev//8243432/webrev.00
> 22 lines changed: 3 ins; 12 del; 7 mod;

Thanks,
-- Igor