[llvm] [LowerMemIntrinsics] Factor control flow generation out of the memcpy lowering (PR #169039)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

> For reference this is not an optimization, and is mandatory.
> 
> > The bad thing about this whole stugf is that it was enabled by default in
> 
> For reference PreISelIntrinsicLowering started handling memory intrinsics in [3c84819](https://github.com/llvm/llvm-project/commit/3c848194f28decca41b7362f9dd35d4939797724), Wed Jun 7 09:03:17 2023 -0400
> 
> The recent change just started shuffling where the RuntimeLibcallsInfo comes from

flang is part of LLVM for a long time, you should update it accordingly, just like you did it for clang

https://github.com/llvm/llvm-project/pull/169039