RFR: 8318834: Debug builds are missing debug helpers

[Andrew Haley]

On s390x only, HotSpot is built by GCC with -ffunction-sections.
This means that debug helpers such as ps() and pfl() are not available. These helpers are extremely useful in debugging, so it makes no sense to omit them from debug builds.

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Commit messages:
 - 8318834: Debug builds are missing debug helpers

Changes: https://git.openjdk.org/jdk/pull/16365/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16365&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318834
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/16365.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16365/head:pull/16365

PR: https://git.openjdk.org/jdk/pull/16365