Function max_align_of_generic_param 

pub fn max_align_of_generic_param<'tcx>(
    tcx: TyCtxt<'tcx>,
    caller: DefId,
    ty: Ty<'tcx>,
) -> u64

Max align_of over all implementors of a generic type parameter’s trait bounds (0 for non-param types or a parameter without a bounded set of implementors).