target/arm: Fix sve predicate store, 8 <= VQ <= 15

Brown bag time: store instead of load results in uninitialized temp.


Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1704
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230620134659.817559-1-richard.henderson@linaro.org
Fixes: e6dd5e7 ("target/arm: Use tcg_gen_qemu_{ld, st}_i128 in gen_sve_{ld, st}r")
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/tcg/translate-sve.c

@@ -4329,7 +4329,7 @@ void gen_sve_str(DisasContext *s, TCGv_ptr base, int vofs,
     /* Predicate register stores can be any multiple of 2.  */
     if (len_remain >= 8) {
         t0 = tcg_temp_new_i64();
-        tcg_gen_st_i64(t0, base, vofs + len_align);
+        tcg_gen_ld_i64(t0, base, vofs + len_align);
         tcg_gen_qemu_st_i64(t0, clean_addr, midx, MO_LEUQ | MO_ATOM_NONE);
         len_remain -= 8;
         len_align += 8;