Make StridedArray display as StridedArray

Instead of a huge union.  This is just a special-casing for this particular union instead of pursuing the general (and hard\!) typealias search.  But given the ubiquity of StridedArray in method lists, I find this special case to be warranted and hugely beneficial. Here is a sampling from `methods(*)`:

```julia
[242] *(A::LinearAlgebra.AbstractQ, b::StridedArray{T, 1} where T) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/qr.jl:556
[243] *(A::LinearAlgebra.AbstractQ, B::StridedArray{T, 2} where T) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/qr.jl:568
[244] *(Q::LinearAlgebra.AbstractQ, adjB::LinearAlgebra.Adjoint{#s614,#s613} where #s613<:(StridedArray{T, 1} where T) where #s614) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/qr.jl:623
[245] *(A::StridedArray{T, 2} where T, Q::LinearAlgebra.AbstractQ) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/qr.jl:668
[246] *(A::StridedArray{T, 2} where T, adjB::LinearAlgebra.Adjoint{#s614,#s613} where #s613<:LinearAlgebra.AbstractQ where #s614) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/qr.jl:708
[247] *(A::LinearAlgebra.LQPackedQ, B::StridedArray{T, 1} where T) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/lq.jl:153
[248] *(A::LinearAlgebra.LQPackedQ, adjB::LinearAlgebra.Adjoint{#s614,#s613} where #s613<:(StridedArray{T, 1} where T) where #s614) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/lq.jl:177
[249] *(A::StridedArray{T, 1} where T, adjQ::LinearAlgebra.Adjoint{#s614,#s613} where #s613<:LinearAlgebra.LQPackedQ where #s614) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/lq.jl:216
[250] *(A::StridedArray{T, 1} where T, Q::LinearAlgebra.LQPackedQ) in LinearAlgebra at /home/mbauman/julia/usr/share/julia/stdlib/v1.2/LinearAlgebra/src/lq.jl:240
```

base/show.jl

@@ -425,6 +425,11 @@ function show(io::IO, @nospecialize(x::Type))
         show_datatype(io, x)
         return
     elseif x isa Union
+        if x <: StridedArray && x.a <: DenseArray
+            print(io, "StridedArray")
+            show_delim_array(io, x.a.parameters, '{', ',', '}', false)
+            return
+        end
         print(io, "Union")
         show_delim_array(io, uniontypes(x), '{', ',', '}', false)
         return