[llvm] [NewPM][Hexagon] Add HexagonPassRegistry.def (PR #86244)

[via llvm-commits]

paperchalice wrote:

The test case `hvx-loopidiom-memcpy.ll` may be invalid. There is no different between `opt -march=hexagon -hexagon-loop-idiom -S` and `opt -mtriple=hexagon-- -p no-op-loop -S`.
https://github.com/llvm/llvm-project/blob/90454a609894ab278a87be2b9f5c49714caba8df/llvm/lib/Target/Hexagon/HexagonLoopIdiomRecognition.cpp#L2413-L2416
The condition is always true when invoke `opt -march=hexagon -hexagon-loop-idiom`. 😕

https://github.com/llvm/llvm-project/pull/86244