Support Base.reinterpret()

[green-nsk]

I noticed there was some work to support reinterpret(x, ::UnsafeArray): https://github.com/JuliaArrays/UnsafeArrays.jl/compare/reinterpret

any reason it wasn't merged?

[oschulz]

any reason it wasn't merged?

Uh, not sure anymore. :-)