RFR(S): JDK-8133180 - [TESTBUG] runtime/SharedArchiveFile/SharedStrings.java failed with WhiteBox.class : no such file or directory

[Mikhailo Seledtsov]

Please review this fix to the CDS test bug. See the comments in the bug 
for details.

     JBS: https://bugs.openjdk.java.net/browse/JDK-8133180
     Webrev: http://cr.openjdk.java.net/~mseledtsov/8133180.00/
     Testing:
         - ran the reproducer discussed in the bug description
             rm -Rf JT* test
             jtreg 
/media/data3/hg/9/work01/hs-rt/hotspot/test/testlibrary_tests/ctw/JarDirTest.java
             jtreg 
/media/data3/hg/9/work01/hs-rt/hotspot/test/runtime/SharedArchiveFile/SharedStrings.java

         - ran the CDS tests in concurrent mode
         - running CDS tests via multi-platform build-and-test system
             (in progress)

Thank you,
Misha