RFR(M): 8044186 Introduce a reproducible random generator

[Sergei Kovalev]

Hello all,

Looking for volunteers for review.

I'm working for CR https://bugs.openjdk.java.net/browse/JDK-8044186 that
submitted against tests.

There's the several tests which use randomly generated numbers. It's
needed to introduce a way that provide a common manner to reproduce the
same random sequence, set seed.

There are two possible way to provide seed value:
- system property
- command line arguments.

I chose system property to provide seed value because it could be
obtained in any part of code without additional effort. In case passing
seed value as command line argument we have to introduce additional
logic (and unwanted code) to pass this value in appropriate method.

I introduced factory method getRandomInstance in the file Utility.java
and make reference to this method in all applicable tests.
There is other utility class: Verifier.java. It used in several other
testcases from test/compiler/intrinsics/mathexact/ package. Therefore
many files contains modifications only for jtreg annotations.

I've tested all related tests locally. All tests passed and seed value
printed to the logs.

links:
bug: https://bugs.openjdk.java.net/browse/JDK-8044186
webrev: http://cr.openjdk.java.net/~vlivanov/kovalev/8044186/webrev.01/

-- 
With best regards,
Sergei