[llvm] [DebugInfo][InstCombine] When replacing bswap idiom, add DebugLoc to new insts (PR #114231)

[Stephen Tozer via llvm-commits]

SLTozer wrote:

The policy change patch https://github.com/llvm/llvm-project/pull/115349 hasn't landed yet, but the principle seems to be approved of - in which case, is this patch approved to land?

https://github.com/llvm/llvm-project/pull/114231