RFR(L): 10: JDK-8177728 - [TESTBUG] Improve CDS test utils

[mikhailo]

Please review this enhancement to CDS tests (RFE)

     JBS: https://bugs.openjdk.java.net/browse/JDK-8177728
    Webrevs:
         http://cr.openjdk.java.net/~mseledtsov/8177728.00.hotspot/
         http://cr.openjdk.java.net/~mseledtsov/8177728.00.top/


Here is a brief summary of the improvements:
  - create/use CDS utility methods for common patterns in CDS related tests:
      - creating an testlist
      - creating an archive, checking result
      - executing JVM with the archive
      - checking results and common error patterns

  - use -Xshare:on when executing CDS tests, and use test utilities
    to filter out failures due to inability to map shared archive.
    This is a more deterministic way to execute CDS tests.

  - additional improvements came up as part of this work,
    such as jdk.test.lib.Utils:getTestName()

This work also lays ground for future improvements in this area.


Testing:
     1. Locally: executed affected tests on Linux-x64
        (hotspot/test/runtime/SharedArchiveFile)
        PASS

     2. Automated multi-platform testing
        Running the affected tests on a set of supported platforms.
        IN Progress...

Thank you,
Misha