target-microblaze: Delete unused sign_extend() function

The sign_extend() function is unused; delete it.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

target-microblaze/translate.c

@@ -99,19 +99,6 @@ static const char *special_regnames[] =
     "sr16", "sr17", "sr18"
 };
 
-/* Sign extend at translation time.  */
-static inline int sign_extend(unsigned int val, unsigned int width)
-{
-        int sval;
-
-        /* LSL.  */
-        val <<= 31 - width;
-        sval = val;
-        /* ASR.  */
-        sval >>= 31 - width;
-        return sval;
-}
-
 static inline void t_sync_flags(DisasContext *dc)
 {
     /* Synch the tb dependent flags between translator and runtime.  */