bad printing of Array type

[rmculpepper]

The Array type from the math library prints as what appears to be an internal representation. To clarify, the problem is with the printing of the type itself, not the printing of Array values.

For example, here is the first example from https://docs.racket-lang.org/math/array_quick.html:

> (array #[0 1 2 3 4])
- : #(struct:Array
      (Indexes Index (Boxof Boolean) (-> Void) (-> Indexes Byte))
      #<syntax:build/user/8.18/pkgs/math-lib/math/private/array/typed-array-struct.rkt:56:13 prop:equal+hash>
      #<syntax:build/user/8.18/pkgs/math-lib/math/private/array/typed-array-struct.rkt:55:13 prop:custom-write>
      #<syntax:build/user/8.18/pkgs/math-lib/math/private/array/typed-array-struct.rkt:54:13 prop:custom-print-quotable>)
(array #[0 1 2 3 4])

The printing seems to have changed between Racket 8.3 and 8.4. Here is the same example in https://download.racket-lang.org/releases/8.3/doc/math/array_quick.html, showing the expected output:

> (array #[0 1 2 3 4])
- : (Array Byte)
(array #[0 1 2 3 4])