RFR: 8334681: GenShen: Do not use gtest skip test feature

[William Kemper]

Recent versions of gtest provide a means to skip tests [1]. Unfortunately, the test result parsing in the build counts them as errors and fails the build.

[1] https://google.github.io/googletest/advanced.html#skipping-test-execution

-------------

Commit messages:
 - Test result parser fails skipped tests

Changes: https://git.openjdk.org/shenandoah/pull/452/files
  Webrev: https://webrevs.openjdk.org/?repo=shenandoah&pr=452&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334681
  Stats: 23 lines in 1 file changed: 18 ins; 3 del; 2 mod
  Patch: https://git.openjdk.org/shenandoah/pull/452.diff
  Fetch: git fetch https://git.openjdk.org/shenandoah.git pull/452/head:pull/452

PR: https://git.openjdk.org/shenandoah/pull/452