target/arm: Set ISSIs16Bit in make_issinfo

During the conversion to decodetree, the setting of
ISSIs16Bit got lost.  This causes the guest os to
incorrectly adjust trapping memory operations.

Cc: qemu-stable@nongnu.org
Fixes: 46beb58 ("target/arm: Convert T16, load (literal)")
Reported-by: Jeff Kubascik <jeff.kubascik@dornerworks.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200117004618.2742-3-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 1a1fbc6)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

target/arm/translate.c

@@ -8556,6 +8556,9 @@ static ISSInfo make_issinfo(DisasContext *s, int rd, bool p, bool w)
     /* ISS not valid if writeback */
     if (p && !w) {
         ret = rd;
+        if (s->base.pc_next - s->pc_curr == 2) {
+            ret |= ISSIs16Bit;
+        }
     } else {
         ret = ISSInvalid;
     }