target/arm: Extend vec_reg_offset to larger sizes

Rearrange the arithmetic so that we are agnostic about the total size
of the vector and the size of the element.  This will allow us to index
up to the 32nd byte and with 16-byte elements.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180613015641.5667-2-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
1 file changed