RFR(M) [14] : 8225654 : rework vmTestbase/jit/graph

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev//8225654/webrev.00/index.html
> 2536 lines changed: 354 ins; 787 del; 1395 mod; 


Hi all,

could you please review the patch which reworks vmTestbase/jit/graph to make them more readable and reliable?  that includes the following changes:
 - as none of our cgt* tests used more than 1 thread, all test execution is now done in main thread; 
 - use exception instead of System::exit to signal problems; 
 - replaced ExecDriver execution mode w/ regular 'main'; 
 - make the tests to use reproducible random from jdk.test.lib.Utils ;
 - close filereader opened by jit/graph/Globals ;
 - moved tests to one directory;
 - mark a test as skipped if OOME or SOE happens
 - editorial changes such as adding { }, fixing typos, removing commented code, etc.

webrev: http://cr.openjdk.java.net/~iignatyev//8225654/webrev.00/index.html
JBS: https://bugs.openjdk.java.net/browse/JDK-8225654
testing: test/hotspot/jtreg/vmTestbase/jit/graph on linux-x64,windows-x64,macosx-x64,solaris-sparcv9

Thanks,
-- Igor