[llvm] [GlobalISel] Diagnose inline assembly constraint lowering errors (PR #135782)

[Pierre van Houtryve via llvm-commits]

Pierre-vh wrote:

I added some tests, do you want me to test every message?
It might be difficult because a few situations crash the DAG as well, they're cases that are unsupported in general

https://github.com/llvm/llvm-project/pull/135782