RFR: 8256843: [PPC64] runtime/logging/RedefineClasses.java fails with assert: registers not saved on stack

[Martin Doerr]

Method handle logging is broken in fastdebug builds. Problem is that os::current_frame() doesn't return the right frame in fastdebug builds.

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

Commit messages:
 - 8256843: [PPC64] runtime/logging/RedefineClasses.java fails with assert: registers not saved on stack

Changes: https://git.openjdk.java.net/jdk/pull/1394/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1394&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256843
  Stats: 13 lines in 3 files changed: 0 ins; 8 del; 5 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1394.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1394/head:pull/1394

PR: https://git.openjdk.java.net/jdk/pull/1394