[jdk21u-dev] RFR: 8280120: [IR Framework] Add attribute to @IR to enable/disable IR matching based on the architecture

[Daniel Hu]

Clean backport that adds architecture matching attribute for the IR testing framework. This aims to make future backports involving this attribute to be more convenient; specifically, I'd like to backport [JDK-8319960](https://bugs.openjdk.org/browse/JDK-8319960) afterwards which uses this attribute. Affected tests pass on Linux x64.

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Commit messages:
 - Backport a8549b63674be433617b986f392e4ff7afef5185

Changes: https://git.openjdk.org/jdk21u-dev/pull/946/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=946&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8280120
  Stats: 285 lines in 6 files changed: 280 ins; 1 del; 4 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/946.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/946/head:pull/946

PR: https://git.openjdk.org/jdk21u-dev/pull/946