target/i386: Use aesdec_ISB_ISR_AK

This implements the AESDECLAST instruction.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/i386/ops_sse.h

@@ -2177,12 +2177,12 @@ void glue(helper_aesdec, SUFFIX)(CPUX86State *env, Reg *d, Reg *v, Reg *s)
 
 void glue(helper_aesdeclast, SUFFIX)(CPUX86State *env, Reg *d, Reg *v, Reg *s)
 {
-    int i;
-    Reg st = *v;
-    Reg rk = *s;
+    for (int i = 0; i < SHIFT; i++) {
+        AESState *ad = (AESState *)&d->ZMM_X(i);
+        AESState *st = (AESState *)&v->ZMM_X(i);
+        AESState *rk = (AESState *)&s->ZMM_X(i);
 
-    for (i = 0; i < 8 << SHIFT; i++) {
-        d->B(i) = rk.B(i) ^ (AES_isbox[st.B(AES_ishifts[i & 15] + (i & ~15))]);
+        aesdec_ISB_ISR_AK(ad, st, rk, false);
     }
 }