cmd/internal/obj/sparc64: add FABSD
cmd/internal/obj/sparc64: add FABSD

Also rearrange ci and simplify optab.

Change-Id: Ieb70420f8049d9a42abd343a4156d7bbc837929c

4ad/go,4ad/go,4ad/go,4ad/go,4ad/go,4ad/go,4ad/go,4ad/go