Macro __impl_alt_is_sorted 

#[doc(hidden)]
macro_rules! __impl_alt_is_sorted {
    ($ty:ty, $trait:path) => { ... };
}

Shared is_sorted implementation for ALTREP families.

Generates const HAS_IS_SORTED and fn is_sorted(...) inside an impl block. Used by integer, real, logical, and string families.