[llvm] [X86] Add new #134979 test cases for gather scalar (PR #137416)

[Rohit Aggarwal via llvm-commits]

rohitaggarwal007 wrote:

@RKSimon, I don't have the write permission. I am not able to see the merge branch button. Can you please commit on my behalf?

https://github.com/llvm/llvm-project/pull/137416