RFR[xxs] 8195065 runtime/appcds/ProhibitedPackage.java intermittent failure

[Ioi Lam]

https://bugs.openjdk.java.net/browse/JDK-8195065
http://cr.openjdk.java.net/~iklam/jdk11/8195065-cds-prohibited-package-intermittent-failure.v01/

Summary:

The test uses -Xshare:auto to launch a JVM process. In this sub process, 
the CDS archive would sometimes be disabled due to Address Space Layout 
Randomization, and the process would continue to execution without using 
the archive.

However, the variant of TestCommon.checkExec() used by the test assumes 
that -Xshare:on is used, so the test incorrectly required that that sub 
process must execute with the CDS archive.

The fix is to use a different variant of TestCommon.checkExec() that 
knows that -Xshare:auto is being used.

( You can see this coding pattern in other tests, e.g.,
http://hg.openjdk.java.net/jdk/hs/file/4aa67aba6c85/test/hotspot/jtreg/runtime/appcds/jvmti/ClassFileLoadHookTest.java#l88 
)


Thanks
- Ioi