[llvm] [DWARF] Emit a worst-case prologue_end flag for pathological inputs (PR #107849)

[Orlando Cazalet-Hyams via llvm-commits]

https://github.com/OCHyams commented:

I have another inline question, just to clear up some potential confusion on my part. Otherwise LGTM & I'm happy to _Accept_ once that's resolved.

https://github.com/llvm/llvm-project/pull/107849