[llvm-branch-commits] [llvm] [HLSLSemanticSignatures] Implement the indexed packing of elements (PR #218061)

[Helena Kotas via llvm-branch-commits]

https://github.com/hekota approved this pull request.

LGTM, with the same feedback as on #218060. I think the testing function should be renamed `verifyPacking` and `verifyPackingError`

https://github.com/llvm/llvm-project/pull/218061