Add back missing constants

Author: Tokazama

src/ArrayInterface.jl

@@ -31,6 +31,8 @@ parameterless_type(x::Type) = __parameterless_type(x)
 
 const VecAdjTrans{T,V<:AbstractVector{T}} = Union{Transpose{T,V},Adjoint{T,V}}
 const MatAdjTrans{T,M<:AbstractMatrix{T}} = Union{Transpose{T,M},Adjoint{T,M}}
+const UpTri{T,M} = Union{UpperTriangular{T,M},UnitUpperTriangular{T,M}}
+const LoTri{T,M} = Union{LowerTriangular{T,M},UnitLowerTriangular{T,M}}
 
 @inline static_length(a::UnitRange{T}) where {T} = last(a) - first(a) + oneunit(T)
 @inline static_length(x) = Static.maybe_static(known_length, length, x)