[jdk21u] RFR: 8315020: The macro definition for LoongArch64 zero build is not accurate.

[Ao Qi]

Clean backport to fix the LoongArch64 zero build. This backport would be convenient for some OS distributions in the future, such as Debian.

Additional testing:

- [x] LoongArch Zero release and fastdebug build.

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Commit messages:
 - Backport 725ec0ce1b463b21cd4c5287cf4ccbee53ec7349

Changes: https://git.openjdk.org/jdk21u/pull/109/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk21u&pr=109&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8315020
  Stats: 8 lines in 2 files changed: 4 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk21u/pull/109.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u.git pull/109/head:pull/109

PR: https://git.openjdk.org/jdk21u/pull/109