[llvm] [SLP]Improve/fix subvectors in gather/buildvector nodes handling (PR #104144)

[Florian Mayer via llvm-commits]

fmayer wrote:

> > This CL seems to have changed behavior: https://gist.github.com/fmayer/6030063dfacd2abfb0898a5855949034
> > This IR here generates a program that returns 0 before, and 1 after this change. It seems related to inline asm instructions.
> 
> Must be fixed in [c13bf6d](https://github.com/llvm/llvm-project/commit/c13bf6d4a89b8d62bc6eedf68d810a4584ccc4a8)

I can confirm this fixed it.

https://github.com/llvm/llvm-project/pull/104144