All off these are internal implementation details in the
`thrust::detail` namespace:

Contiguous iterators only:
- `contiguous_iterator_traits`
- `contiguous_iterator_raw_pointer_t`:
- `contiguous_iterator_raw_pointer_cast`

These work on all iterators, but convert to a
raw pointer if given a contiguous iterator.
- `try_unwrap_contiguous_iterator_return_t`
- `try_unwrap_contiguous_iterator`

This test was consuming excessive memory during nvc++ compilation.
Splitting into two TUs should remedy this.

Ran clang-format on the new test files, but the contents are the same.