Better `toString`-s are always welcome. But they won't help out in profiler results. (In stack traces line numbers are included so this isn't an issue.)

You both probably know this, but if you want to get back to a source position from a class name:

```
scala> :javap scala.tools.nsc.typechecker.Typers$Typer$$anonfun$typedDefDef$3
...
  LineNumberTable:
   line 2283: 0
```