fixup list of valid as casts

`&m1 T -> *m2 T` is not specific to `as` casts (it's a coercion!), but
`*[T; N]` -> `*T` is! (previously only the reference source version was
documented)

Author: WaffleLapkin

src/expressions/operator-expr.md

@@ -463,8 +463,8 @@ reference types and `mut` or `const` in pointer types.
 | `*T`                  | `*V` where `V: Sized` \* | Pointer to pointer cast       |
 | `*T` where `T: Sized` | Integer type          | Pointer to address cast          |
 | Integer type          | `*V` where `V: Sized` | Address to pointer cast          |
-| `&m₁ T`               | `*m₂ T` \*\*          | Reference to pointer cast        |
 | `&m₁ [T; n]`          | `*m₂ T` \*\*          | Array to pointer cast            |
+| `*m₁ [T; n]`          | `*m₂ T` \*\*          | Array to pointer cast            |
 | [Function item]       | [Function pointer]    | Function item to function pointer cast |
 | [Function item]       | `*V` where `V: Sized` | Function item to pointer cast    |
 | [Function item]       | Integer               | Function item to address cast    |