Macro require_validity 

macro_rules! require_validity {
    ($parent:expr, $idx:expr) => { ... };
}

Require that the validity slot is a Bool array. If validity is not array-backed (e.g. NonNullable or AllValid), this is a no-op. If it is array-backed but not Bool, early-returns an ExecutionResult requesting execution of the validity slot.

Like require_opt_child!, $parent is moved (not cloned) into the early-return path.

require_validity!(array, VALIDITY_SLOT);