RFR: 8261929: ClhsdbFindPC fails with java.lang.RuntimeException: 'In java stack' missing from stdout/stderr

[Chris Plummer]

Sometimes due to the state of the java thread, jstack does cannot determine the address of the java frame and instead it is 0x. We need to special case this so the test does not fail.

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

Commit messages:
 - Special case when we can't get the address of the java stack.

Changes: https://git.openjdk.java.net/jdk/pull/2637/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2637&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8261929
  Stats: 9 lines in 1 file changed: 4 ins; 0 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2637.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2637/head:pull/2637

PR: https://git.openjdk.java.net/jdk/pull/2637