[llvm] [X86] Use X86FixupInstTunings to select between (V)MOVSS/D and (V)BLENDPS/D (PR #143895)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

I think this is due to the flang failure upstream - I've merged against trunk again to see if we can clear it

https://github.com/llvm/llvm-project/pull/143895