[clang] [AArch64][SVE] Fold svrev(svrev(v)) to v (PR #116422)

[Benjamin Maxwell via cfe-commits]

https://github.com/MacDue commented:

Nit on the title. Could the title be something like: `[Arch64][SVE] Lower svrev_* to llvm.vector.reverse`? Since nothing in this PR is doing the folding (I think the description saying this enables the fold is good).

https://github.com/llvm/llvm-project/pull/116422