[llvm] [DebugInfo] Don't set prologue_end behind line-zero call insts (PR #156850)

[Jeremy Morse via llvm-commits]

jmorse wrote:

I suppose the major risk would be attaching a non-zero source location to an instruction that then traps and gets reported in a backtrace... but it's already a disaster if that happens I suppose. If the new source-location inserted was applied to the call, a stack-trace would also present the scope-line in a backtrace... which again is a bit more information than just line zero.

I'll see what our debugger folks think.

https://github.com/llvm/llvm-project/pull/156850