[llvm] Fix to account for multiple ISA enumeration (PR #118676)

[Joseph Huber via llvm-commits]

https://github.com/jhuber6 approved this pull request.

Good short-term fix, long term we just need to handle multiple of these and push them back. Then we can scan all the ISAs from least generic  to most generic through some complicated lookup table.

https://github.com/llvm/llvm-project/pull/118676