RFR(S): 8142874: [TESTBUG] OptionsValidation testing framework needs to handle VM error codes in some cases

[Dmitry Dmitriev]

Hello,

Please review this small enhancement to the command line options 
validation test framework. This enhancement allow to specify allowed 
exit code for flags. This is needed for CDS Shared flags, because in 
some cases JVM can exit with error code 2 and this should not be treated 
as error. Also, in this fix I refactor code which parse Shared flags - 
specify explicit names of the flags in switch statement and use only one 
CDS archive file.

JBS: https://bugs.openjdk.java.net/browse/JDK-8142874
webrev: http://cr.openjdk.java.net/~ddmitriev/8142874/webrev.01/ 
<http://cr.openjdk.java.net/%7Eddmitriev/8142874/webrev.01/>
Testing: tested on all platforms by RBT

Thanks,
Dmitry