tcg-aarch64: Enable builtin disassembler

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>

configure

diff --git a/configure b/configure
index 8689435..af44b6a 100755
--- a/configure
+++ b/configure
@@ -4968,6 +4968,12 @@
     echo "CONFIG_ALPHA_DIS=y"  >> $config_target_mak
     echo "CONFIG_ALPHA_DIS=y"  >> config-all-disas.mak
   ;;
+  aarch64)
+    if test -n "${cxx}"; then
+      echo "CONFIG_ARM_A64_DIS=y"  >> $config_target_mak
+      echo "CONFIG_ARM_A64_DIS=y"  >> config-all-disas.mak
+    fi
+  ;;
   arm)
     echo "CONFIG_ARM_DIS=y"  >> $config_target_mak
     echo "CONFIG_ARM_DIS=y"  >> config-all-disas.mak