transpile: Outer `override_ty` is not propagated through array-to-pointer casts

[Rua]

Noted by kkysen (#1628 (comment)), and also demonstrated by #1571 (comment).

When an override_ty has to pass through an array-to-pointer cast, it is not propagated to the expression inside the cast. That means that, for example, if the outer expression/variable has type *const wchar_t and the inner array is [c_int; N], the wchar_t pointee type is not propagated to override the element type c_int of the original array. Instead, a cast to the pointer type gets added at the end.

[fw-immunant]

See #1645 for a sketch of a fix for this. I'm not very happy with how it looks, so I decided to share its current state as this isn't high priority right now and runs into some technical brittleness of the transpiler fairly badly.

[Rua]

Just noticed that this also happens with the address-of operator, when taking the address of a string literal and assigning it to a pointer-to-fixed-size-array.