RFR (S): 8190703: TestSystemGCWith* infrequently times out on SPARC

[Thomas Schatzl]

Hi all,

  can I have reviews for this change the fixes intermittent timeouts in
a stress test when run on slow machines and debug builds.

The fix is to simply let the test bail out early if time is up - this
allows the test run through as intended in the many configurations
where it does not take excessive amount of time.

CR:
https://bugs.openjdk.java.net/browse/JDK-8190703
Webrev:
http://cr.openjdk.java.net/~tschatzl/8190703/webrev
Testing:
Ran the specific tests in our test lab on slow configurations (SPARCv9,
debug build), checking manually that they do not exceed their specified
time out.

Thanks,
  Thomas