Tests that functions named `.` are rendered correctly.

``` unison
(`.`) f g x = f (g x)

use Boolean not

noop = not `.` not
```

``` ucm

  Loading changes detected in scratch.u.

  I found and typechecked these definitions in scratch.u. If you
  do an `add` or `update`, here's how your codebase would
  change:
  
    ⍟ These new definitions are ok to `add`:
    
      `.`  : (i1 ->{g1} o) -> (i ->{g} i1) -> i ->{g1, g} o
      noop : Boolean -> Boolean

```
``` ucm
scratch/main> add

  ⍟ I've added these definitions:
  
    `.`  : (i1 ->{g1} o) -> (i ->{g} i1) -> i ->{g1, g} o
    noop : Boolean -> Boolean

scratch/main> view noop

  noop : Boolean -> Boolean
  noop =
    use Boolean not
    not `.` not

```