RFR: 8336163: Remove declarations of some debug-only methods in release build

[Qizheng Xing]

Some of the methods are defined only in debug mode, but their declarations still exist in release mode.

This is considered a bug because these methods may be called mistakenly in release mode and cause the build to fail.

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Commit messages:
 - Do not declare some of the methods in release mode.

Changes: https://git.openjdk.org/jdk/pull/20131/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20131&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8336163
  Stats: 16 lines in 5 files changed: 16 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20131.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20131/head:pull/20131

PR: https://git.openjdk.org/jdk/pull/20131