[llvm] [tools][llc] Add `--save-stats` option (PR #163967)

[Matthias Braun via llvm-commits]

MatzeB wrote:

Would a simpler version work that just takes a filename instead of all the logic with `cwd` / `obj`[1]

[1] I think the logic kinda makes sense for the clang driver which naturally does this sort of transformation and filename construction all the time; but for these small developers tools within LLVM it seems overkill...

https://github.com/llvm/llvm-project/pull/163967