fix build

Should fix the build that was breaking with some errors like:

    error: failed to find an implementation of trait core::fmt::Show for [int,.. 16]

the issue is that with the ongoing work on DST,  `&[1, 2]` (creating a vector and taking a slice) has changed from returning a `&[int]` to returning a `&[int,..2]` and fixed sized vectors don't implement traits like Show or Eq.

Fix is changing from code like:

````rust
let vec = &[1, 2];
do_something_witth(vec);
````

to

````rust
let vec = [1, 2];
do_something_witth(vec.as_slice());
````