[llvm] [RISCV][GlobalISel] Select G_GLOBAL_VALUE (PR #70091)

[Craig Topper via llvm-commits]

topperc wrote:

> > PR #68380 tried to create special instructions to do this, but I don't see why we need to do that.
> 
> Presumably "because SDAG does". Though I still to this day don't understand the point of most of those SDAG indirections; we used to just create the machine nodes directly. Seemed to just add a bunch of busywork jumping between different equivalent forms.

The only that was probably actually needed was RISCVISD::ADD_LO for RISCVDAGToDAGISel::SelectAddrRegImm.

https://github.com/llvm/llvm-project/pull/70091