[llvm] Add the 'initializes' attribute langref and support (PR #84803)

[Arthur Eubanks via llvm-commits]

https://github.com/aeubanks commented:

looks pretty good to me. I would like to take a look at the inference and DSE patches to make sure they look good at a high level before merging this one

https://github.com/llvm/llvm-project/pull/84803