Implement Short Floating-Point Store Instructions as described
in the chapter 13.5.2 of UltraSPARC-IIi User's Manual.

Particularly this instructions are used by NetBSD 4.0.1+ /sparc64

Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>