target-arm: A64: add support for logical (immediate) insns

target-arm: A64: add support for logical (immediate) insns

This patch adds support for C3.4.4 Logical (immediate),
which include AND, ANDS, ORR, EOR.

Signed-off-by: Alexander Graf <agraf@suse.de>
[claudio: adapted to new decoder, function renaming,
          removed a TCG temp variable]
Signed-off-by: Claudio Fontana <claudio.fontana@linaro.org>
[PMM: cleaned up some unnecessary code in logic_imm_decode_wmask
and added clarifying commentary on what it's actually doing.
Dropped an ext32u that's not needed if we've just done an AND.]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>