RFR(S) : 8242314 : use reproducible random in vmTestbase shared code

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev/8242314/webrev.00/ 
> 122 lines changed: 71 ins; 19 del; 32 mod;


Hi all,

could you please review this small patch which updates shared vmTestbase  test code to use j.t.l.Utils.getRandomInstance() as a random number generator or as a source of seed values? this patch lays the ground work for updates of :vmTestbase_* test groups which are to be done by remaining subtasks of 8241623[1], such split make it possible to work on/review/test testgroup-specific changes in concurrently.  
 
unfortunately, such extra dependency on /test/lib classes broke the shaky balance and caused some tests to fail due to "split testlibrary" problem (see 8188828[2] for the definition), the solution to that is to remove all dependencies on /test/lib classes from ExecDriver class, so the patch also includes "inlining" of several jdk.test.lib.Utils and Platform methods/fields into ExecDriver.

webrev: http://cr.openjdk.java.net/~iignatyev/8242314/webrev.00/ 
testing: all :vmTestbase_* test groups on {linux,windows,macosx}-x64 and solaris-sparcv9
JBS: https://bugs.openjdk.java.net/browse/JDK-8242314

[1] https://bugs.openjdk.java.net/browse/JDK-8241623
[2] https://bugs.openjdk.java.net/browse/JDK-8188828

Thanks,
-- Igor