cmd/internal/obj/sparc64: add RT1, RT2, and CTXT
cmd/internal/obj/sparc64: add RT1, RT2, and CTXT

Change-Id: I356eda2a160047a7f0614cc8783546feaad02341

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