[llvm] Fix `llvm/test/DebugInfo/Generic/discriminated-union.ll` on big-endian targets (PR #125849)

[David Blaikie via llvm-commits]

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

That is some snazzy new (probably not that new, but first I've seen it) FileCheck stuff - awesome :)

Thanks for the fix!

https://github.com/llvm/llvm-project/pull/125849