RFR: 8347422: Crash during safepoint handler execution with -XX:+UseAPX [v2]

[Jatin Bhateja]

> This bug fix patch fixes an internal error seen during safepoint handler execution.
> The problem occurs due to missing handling for REX2 prefixed polling test instruction.
> 
> Manually verified the patch with the -XX:+SafepointALot runtime flag.
> 
> Best Regards,
> Jatin
> PS: Patch will be opened for review after some validation.

Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:

  Review comments resolution.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/23035/files
  - new: https://git.openjdk.org/jdk/pull/23035/files/4071a9d1..be72373e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23035&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23035&range=00-01

  Stats: 6 lines in 1 file changed: 0 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/23035.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23035/head:pull/23035

PR: https://git.openjdk.org/jdk/pull/23035