[llvm] [utils][UpdateTestChecks] Warn about possible target triple mismatch (PR #149645)

[Florian Hahn via llvm-commits]

https://github.com/fhahn commented:

> @fhahn A test case would have to use a triple supported by llc but not by `llvm/utils/UpdateTestChecks/asm.py`. I have only one at hand: `arm64-apple-darwin`. But I may add next support for `arm64-apple` and `aarch64-apple` as prefixes in `llvm/utils/UpdateTestChecks/asm.py` and invalidate the test. This is also mainly a logging change. Thus I suggest to not require a test in this case.

Why would such a change invalidate the test? It would just be updated to show the new behavior?

https://github.com/llvm/llvm-project/pull/149645