[llvm] [DebugInfo] Add clang flag to enable function-level debug line attribution (PR #93985)

[David Blaikie via llvm-commits]

dwblaikie wrote:

I don't think it's possible to know that constant without essentially modeling everything the assembler would do (to know how large various encodings are, etc) - which is probably not portable (exactly how an assembler encodes the line table may vary between implementations, maybe between uses of a single implementation (might be able to enable different kinds of relaxation etc))

https://github.com/llvm/llvm-project/pull/93985