[jdk25u-dev] RFR: 8370378: Some compiler tests inadvertently exclude particular platforms

[Roland Mesde]

Backporting JDK-8370378: Some compiler tests inadvertently exclude particular platforms.

For parity with Oracle JDK.

This commit updates the @requires annotations to include both "amd64" and "x86_64" values to ensure tests run on all x86_64 platforms regardless of OS.

Ran the specific test on linux-x64 (amd64), linux-aarch64, macos-aarch64 and windows-x64 (amd64). Testing on macOS x86_64 was not performed due to platform unavailability.:

(Passed) - make test TEST=test/hotspot/jtreg/compiler/c2/TestBit.java
(Passed) - make test TEST=test/hotspot/jtreg/compiler/c2/irTests/RotateLeftNodeIntIdealizationTests.java
(Passed) - make test TEST=test/hotspot/jtreg/compiler/c2/irTests/RotateLeftNodeLongIdealizationTests.java

-------------

Commit messages:
 - Backport 60104575b221eb3d78a4d56839d55953d4036c21

Changes: https://git.openjdk.org/jdk25u-dev/pull/113/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u-dev&pr=113&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8370378
  Stats: 5 lines in 3 files changed: 0 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk25u-dev/pull/113.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u-dev.git pull/113/head:pull/113

PR: https://git.openjdk.org/jdk25u-dev/pull/113