target/arm: Convert rax1 to gvec helpers

With this conversion, we will be able to use the same helpers
with sve.  This also fixes a bug in which we failed to clear
the high bits of the SVE register after an AdvSIMD operation.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200514212831.31248-3-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
4 files changed