[llvm] [DebugInfo][DWARF] Set is_stmt on first non-line-0 instruction in BB (PR #105524)

[Stephen Tozer via llvm-commits]

SLTozer wrote:

> Might be worth reverting this and reconsidering whether the growth is acceptable or whether there's a more targeted fix that can be made?

I have another patch up now that tries to be more cautious with its application of is_stmt: https://github.com/llvm/llvm-project/pull/108251

It currently needs a fix, and confirmation that it has suitable performance, but it should result in fewer is_stmts being applied. With that said, if it doesn't bring the numbers down that much, there is a reasonable question about correctness vs size - it might not be feasible to compute the minimum set of is_stmts that don't result in missing steps, so there might be either a tradeoff to make, or a flag to add.


https://github.com/llvm/llvm-project/pull/105524