Go-to-definition doesn't work when a file exists but is not a module

```ts
// @filename: scriptThing.ts
console.log("woooo side effects")

// @filename: stylez.css
div {
  color: magenta;
}

// @filename: moduleThing.ts

// not a module, but we should let you jump to it.
import /*1*/"./scriptThing";

// not JS/TS, but if we can, you should be able to jump to it.
import /*2*/"./stylez.css";
```

Go to definition on `/*1*/` and `/*2*/` should work!