[clang] [DebugInfo] Correct the line attribution for IF branches (PR #108300)

[Paul T Robinson via cfe-commits]

pogo59 wrote:

This fixes the problem I describe in https://discourse.llvm.org/t/wrong-scope-in-dbg-on-a-branch-or-how-to-find-branchinst-create/81112

https://github.com/llvm/llvm-project/pull/108300