This patch adds the Load VSX Vector Word*4 Indexed (lxvw4x)
instruction.

V2: changed to use deposit_i64 per Richard Henderson's review.
Signed-off-by: NTom Musta <tommusta@gmail.com>
Reviewed-by: NRichard Henderson <rth@twiddle.net>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>