Return-by-reference round-trip failure

```
fn getx(a: {x: int}, _b: int) -> &!1 int { ret a.x; }
fn main() { assert getx({x:3}, 4) == 3; }
```

The first line is pretty-printed without a space:

```
fn getx(a: {x: int}, _b: int) -> &!1int { ret a.x; }
```

And then the "i" in "int" gets eaten:

```
fn getx(a: {x: int}, _b: int) -> &!1nt { ret a.x; }
```

I'm not sure which step is the bug.
