[AArch64] Redundant AllOne/AllZero patterns?

[Tim Northover]

> def Neon_AllZero : PatFrag<(ops), (Neon_movi (i32 0), (i32 14))>;
> def Neon_AllOne : PatFrag<(ops), (Neon_movi (i32 255), (i32 14))>;
>
> Are these redundant?  If so, which should we prefer?

They look it. Personally, I prefer these newer ones, though some
comment on these special numbers might be in order.

Cheers.

Tim.