RFR(S/T) : 8244385 : various clean-ups in runtime tests

[Igor Ignatyev]

http://cr.openjdk.java.net/~iignatyev//8244385/webrev.00
> 324 lines changed: 57 ins; 80 del; 187 mod;

Hi all,

could you please review these small clean ups in runtime tests?
from JBS:
> there were some leftovers from my previous clean-ups in runtime: 
>  - some tests can be switched to use driver-mode 
>  - some tests miss exit code checks 
>  - some tests can use @requires instead of if-s 
>  - TestInheritFD should use jtreg.SkippedException instead of silent exit

changes in two files might require some highlighting:  
- runtime/CompressedOops/CompressedClassSpaceSize.java isn't executed on 32bit platforms b/c of @requires, so L#101-108 are effectively dead code.
- switching to @requires in  runtime/cds/appcds/TestZGCWithCDS.java removed the need for WhiteBox API and make it possible to use driver-mode

PS these changes are unrelated, yet I find that splitting it into several patches just create more noise w/ very little value, however if people believe it's better to split this patch into several separate patches for ease of reviewing, backporting, tracking, or any other reasons, I will do that.

JBS: https://bugs.openjdk.java.net/browse/JDK-8244385
webrev: http://cr.openjdk.java.net/~iignatyev//8244385/webrev.00
testing: the changed tests

Thanks,
-- Igor