Inlining and Desugar passes should preserve type information

Currently we re-type check after inlining and desugaring.

This is fine expect for one edge case.

```elm
doubleDouble : Double -> Double
doubleDouble x = x * 2

feature incorrect =
  from something in doubleDouble 4
```

After inlining, this will type check as `Num a => a` and the defaulting rules will
make it an `Int` instead of a `Double`.