RFR: 8227615: [TESTBUG] Fix jtreg "jdk/sun/security/util/FilePermCompat/CompatImpact.java" failing with graal issue.

[Xiaohong Gong (Arm Technology China)]

Hi,

  Please help to review this small patch:
  Webrev: http://cr.openjdk.java.net/~pli/rfr/8227615/webrev.00/
  JBS: https://bugs.openjdk.java.net/browse/JDK-8227615

  Jtreg test "jdk/sun/security/util/FilePermCompat/CompatImpact.java" fails due to access denied to JVMCI runtime with graal mode.
  This patch fixes the permission issue by making the application's own policy extending the default system policy. Besides it also fixes
the stderr file couldn't be found issue by renaming the file name to the right one.

Thanks,
Xiaohong Gong