[llvm] [InstCombine] Match scalable splats in m_ImmConstant (PR #132522)

[Luke Lau via llvm-commits]

lukel97 wrote:

@antmox I was able to reproduce it locally and it goes away without this patch, thanks for pointing me to it. Reverted now in b61e387

https://github.com/llvm/llvm-project/pull/132522