[llvm] [PowerPC] Legalize i8 for read/write global name registers (PR #180805)

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Is there a reason we don't want this explicitly for these ops? 

These are not abstract operations. They correspond to direct register access. I don't think it makes sense to legalize this, any more than it would to try to make illegal inline assembly work 

> For backward compact with XL compilers on powerpc, 

End users don't have direct access to intrinsics?

https://github.com/llvm/llvm-project/pull/180805