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

[Sushant Gokhale via llvm-commits]

sushgokh wrote:

@alexey-bataev 
>REQUIRES: x86, aarch64
Does not this mean that the supported host architecture must be x86/aarch64 ? We just want to run the tests for x86/aarch64 which is indicated by the -mtriple option and hence, it wont run for other triples.

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