target/arm: Add read/write_neon_element32

Model these off the aa64 read/write_vec_element functions.
Use it within translate-neon.c.inc.  The new functions do
not allocate or free temps, so this rearranges the calling
code a bit.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201030022618.785675-6-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2 files changed