RISC-V support

[Jim Wilson]

On Sat, Jan 12, 2019 at 5:23 PM Kurt Roeckx <kurt@roeckx.be> wrote:
> O32 really has at least the following variants:
> - O32 FP32
> - O32 FPXX
> - O32 FP64
> - O32 FP64A

The FPXX and FP64A stuff is new, after I stopped tracking MIPS stuff,
so I hadn't noticed it.  I see why they added these, but if you count
soft-float, single-float, no-float, and a now deprecated 64-bit FP reg
mode, there are 8 different ways to handle FP code for o32.  Crazy.
Most of them aren't relevant to linux though.  And I suppose 20-30
years from now RISC-V may have the same problem.

Jim