[llvm] [Transforms][IPO] Add remarks for ArgumentPromotion and DeadArgumentE… (PR #105740)

[David Li via llvm-commits]

https://github.com/david-xl commented:

bike shedding on the format. Is it better to show the parameter name first in the message?

foo: eliminating argument 'x' (index 0)
foo: promoting argument 'p'(index 1) to pass by value

https://github.com/llvm/llvm-project/pull/105740