[llvm] [X86] combineConcatVectorOps - concat per-lane v2f64/v4f64 shuffles into vXf64 vshufpd (PR #143017)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

Thanks - it looks like its awakened a latent bug in load combining (which hasn't been touched for a long time......)

https://github.com/llvm/llvm-project/pull/143017