[llvm] [Analysis] Add Scalable field in MemoryLocation.h (PR #65759)

[David Green via llvm-commits]

https://github.com/davemgreen commented:

I've been looking through the uses of MemoryLocation and this couldn't see any other cases that immediately look like they would cause problems. I dont have a strong opinions on whether the DSE handling should be here or done as a separate patch. It probably makes sense to keep them separate. @nikic any thoughts?

https://github.com/llvm/llvm-project/pull/65759