RFR: 8354215: Clean up Loom support after 32-bit x86 removal

[Aleksey Shipilev]

Small cleanup, we do not need this code anymore. This effectively reverts [JDK-8288040](https://bugs.openjdk.org/browse/JDK-8288040).

Additional testing:
 - [ ] GHA

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Commit messages:
 - Also one remaining bit
 - Fix

Changes: https://git.openjdk.org/jdk/pull/24591/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24591&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354215
  Stats: 57 lines in 3 files changed: 0 ins; 56 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/24591.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24591/head:pull/24591

PR: https://git.openjdk.org/jdk/pull/24591