[llvm] Fix line table lookups in line tables with multiple lines with the sa… (PR #70879)

[David Blaikie via llvm-commits]

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

FWIW this looks right to me (& at some point it'd be nice to fix LLVM to never produce these zero-length entries, they just take up extra space in the line table for no benefit)

https://github.com/llvm/llvm-project/pull/70879