[llvm] [llvm-mca] Abort on parse error without -skip-unsupported-instructions (PR #90474)

[Peter Waller via llvm-commits]

peterwaller-arm wrote:

Thanks for helping find consensus. I found one more issue which I've addressed: there were some thumb and other target=ARM instructions which weren't parsing. Rather than skip them I've fixed them in situ. I'll merge when I return to work on Tuesday next week assuming that CI is green or there are only trivial things to fix.

https://github.com/llvm/llvm-project/pull/90474