RFR: 8354215: Clean up Loom support after 32-bit x86 removal [v2]

[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

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Touchups

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24591/files
  - new: https://git.openjdk.org/jdk/pull/24591/files/f5f7a8cf..5adc1c90

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24591&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24591&range=00-01

  Stats: 16 lines in 1 file changed: 0 ins; 6 del; 10 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