target/arm: Clear high SVE elements in handle_vec_simd_wshli

target/arm: Clear high SVE elements in handle_vec_simd_wshli

AdvSIMD instructions are supposed to zero bits beyond 128.
Affects SSHLL, USHLL, SSHLL2, USHLL2.

Cc: qemu-stable@nongnu.org
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240717060903.205098-15-richard.henderson@linaro.org
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
(cherry picked from commit 8e0c9a9efa21a16190cbac288e414bbf1d80f639)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>