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

[Nashe Mncube via llvm-commits]

nasherm wrote:

> Can we replace all the uses of the old global with the new one, to make sure we don't end up with many repeated globals? i.e use the first n bytes of the now wider global in the "other" uses, and hopefully re-use the already widened global in other allocas that are also widened. (Or widen all uses at once, or maybe just limit it to a single use if it isn't very useful)

I have something that works by not creating multiple globals. It rather creates the new global and updates all the references, but doesn't update the original source global. I'm not sure if this is an ideal solution. 

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