"\w!\w" should treat the bang as part of the atom

```ex
iex(4)> hello!world
error: undefined function hello!/1 (there is no such import)
└─ iex:4

** (CompileError) cannot compile code (errors have been logged)
```

Practical example:

```ex
registry = start_supervised!(KV.Registry)
```

Currently maps to `'elixirOperator'`