RFR: 8374744: Enable dumping of APX EGPRs (R16–R31) in JVM fatal error logs [v2]

[Srinivas Vamsi Parasa]

> The goal of this PR is to add support for printing the values of APX extended general-purpose registers (EGPRs, R16-R31) in hs_err_pid* crash logs on x86 platforms with APX support. The implementation detects APX support at runtime and attempts to dump the additional registers when available, improving post-mortem debugging capabilities.

Srinivas Vamsi Parasa has updated the pull request incrementally with one additional commit since the last revision:

  undo verbose code to print registers; repalce it with for loop

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Changes:
  - all: https://git.openjdk.org/jdk/pull/29098/files
  - new: https://git.openjdk.org/jdk/pull/29098/files/a052e848..40ffe2d6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=29098&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=29098&range=00-01

  Stats: 42 lines in 1 file changed: 0 ins; 34 del; 8 mod
  Patch: https://git.openjdk.org/jdk/pull/29098.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29098/head:pull/29098

PR: https://git.openjdk.org/jdk/pull/29098