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

[Elvina Yakubova via llvm-commits]

ElvinaYakubova wrote:

> If the llvm compiled without x86 or aarch64, it still tries to run all the tests. These tests will fail, because llvm won't be able execute them successfully. To prevent their unconditional execution, need to add special directives that checks if the compiler supports given target. Or put them in the corresponding directories, where config files do the same - check if the llvm support given target before running the tests in the given directories.

Thanks for the explanation. I updated the commit with REQUIRES since we don't want to duplicate tests 

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