[llvm] [RemoveDIs][DebugInfo] Add support for DPValues to LoopStrengthReduce (PR #78706)

[Jeremy Morse via llvm-commits]

https://github.com/jmorse commented:

Looks good, with a nit inline, it just wants `--try-experimental-debuginfo-iterators` adding to the lit tests that cover this code.

https://github.com/llvm/llvm-project/pull/78706