[llvm] [llvm][ARM]Add ARM widen strings pass (PR #107120)

[David Green via llvm-commits]

davemgreen wrote:

I believe there was talk a long time ago about adding this to an existing pass such as the GlobalOpts pass or CGP. It sounds like CGP is too late for it, could it be a part of GlobalOpt or some other pass?

https://github.com/llvm/llvm-project/pull/107120