[llvm] [SandboxVec] Implement Pass class (PR #107617)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

Are they vectoriser specific? Alternative place them here:
https://github.com/llvm/llvm-project/tree/main/llvm/include/llvm/SandboxIR
?

https://github.com/llvm/llvm-project/pull/107617