Correct sign-propagation before multiplication in MULQ_W helper.
The change also fixes previously incorrect expected values in the
tests for MULQ_RS.W and MULQ_S.W.
Signed-off-by: Petar Jovanovic <petarj@mips.com>
Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>