[llvm] [BranchFolder] Fix missing debug info with tail merging (PR #94715)

[Jeremy Morse via llvm-commits]

https://github.com/jmorse commented:

It looks like the changes to the COFF test file are because a jmp without a source location previously inherited an earlier source-location, but now gets it's own source location. That causes:
 * A new label to appear in the assembly to help describe ranges,
 * A variable's scope range to reduce slightly,
 * A lexical scope (I think?) and another variable to reduce range slightly.
Which I think is consistent with what you're doing here, the jmp previously inherited being "inside" an inlined function, but now the source location is preserved it really belongs to the outer function.

https://github.com/llvm/llvm-project/pull/94715