8373724: [BACKOUT] RA support for EVEX to REX/REX2 demotion to optimize NDD instructions

[missa-prime]

This is to resolve regressions caused by #26283.

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8373724: [BACKOUT] RA support for EVEX to REX/REX2 demotion to optimize NDD instructions (Bug - P3)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/28972/head:pull/28972
$ git checkout pull/28972

Update a local copy of the PR:
$ git checkout pull/28972
$ git pull https://git.openjdk.org/jdk.git pull/28972/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 28972

View PR using the GUI difftool:
$ git pr show -t 28972

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/28972.diff

[bridgekeeper]

👋 Welcome back missa! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

@missa-prime The following label will be automatically applied to this pull request:

• hotspot-compiler

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.