target/arm: Fix temp double-free in sve ldr/str

The temp that gets assigned to clean_addr has been allocated with
new_tmp_a64, which means that it will be freed at the end of the
instruction.  Freeing it earlier leads to assertion failure.

The loop creates a complication, in which we allocate a new local
temp, which does need freeing, and the final code path is shared
between the loop and non-loop.

Fix this complication by adding new_tmp_a64_local so that the new
local temp is freed at the end, and can be treated exactly like
the non-loop path.

Fixes: bba87d0a0f
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200702175605.1987125-1-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/translate-a64.c

@@ -461,6 +461,12 @@ TCGv_i64 new_tmp_a64(DisasContext *s)
     return s->tmp_a64[s->tmp_a64_count++] = tcg_temp_new_i64();
 }
 
+TCGv_i64 new_tmp_a64_local(DisasContext *s)
+{
+    assert(s->tmp_a64_count < TMP_A64_MAX);
+    return s->tmp_a64[s->tmp_a64_count++] = tcg_temp_local_new_i64();
+}
+
 TCGv_i64 new_tmp_a64_zero(DisasContext *s)
 {
     TCGv_i64 t = new_tmp_a64(s);