Better error message for missing source files

After renaming a source file, cabal produces the following error message:

```
cabal.exe: can't find source for Old/Name/Of/Module in src, dist/build/autogen
```

The problem is that the old module name still occurs in the cabal file. It would be better if cabal could point me to the line in the `*.cabal` file that I have to change. For example:

```
example-project.cabal:123: Can't find source for ...
```

This would enable my editor to auto-jump to the problematic line.