RFR: 8322985: [BACKOUT] 8318562: Computational test more than 2x slower when AVX instructions are used

Fri Jan 5 13:49:33 UTC 2024

[JDK-8318562](https://bugs.openjdk.org/browse/JDK-8318562) broke implicit null checking for cvt instructions. See JBS for details. Let's back it out for now because this is a potential showstopper for JDK 17.0.11, 21.0.2 and 22 and needs to be backported asap.

The backout applies cleanly.

Thanks,
Tobias

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Commit messages:
 - Revert "8318562: Computational test more than 2x slower when AVX instructions are used"

Changes: https://git.openjdk.org/jdk/pull/17279/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17279&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8322985
  Stats: 247 lines in 4 files changed: 0 ins; 245 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17279.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17279/head:pull/17279

PR: https://git.openjdk.org/jdk/pull/17279