[llvm] [SLP] Move some of X86 tests to common directory (PR #106401)

[Florian Hahn via llvm-commits]

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@@ -1,5 +1,7 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; REQUIRES: target={{aarch64|x86_64}}-{{.*}}
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fhahn wrote:

If it helps, the above is for ARM64 macOS

https://github.com/llvm/llvm-project/pull/106401