[llvm] [Analysis][AArch64] Add cost model for loop.dependence.{war/raw}.mask (PR #167551)

[Benjamin Maxwell via llvm-commits]

MacDue wrote:

I'll wait till https://github.com/llvm/llvm-project/pull/168565 lands before merging this (otherwise, this does not match the codegen). 

https://github.com/llvm/llvm-project/pull/167551