sort(x::Matrix; dims) bypasses fpsort!

[LilithHafner]

This is because sort(::Matrix; dims) calls the 6-argument sort!(::AbstractVector, lo::Integer, hi::Integer, ::Algorithm, ::Ordering, temp) and the lack of lo and hi arguments is what triggers dispatch to fpsort!. This also precludes the use of radix sort on sort(::Matrix; dims).