Useless empty C files with arc/orc
When compiling with arc/orc or more likely with `--exceptions:goto` a C file will be gneerated for each import or import dependency even if it's unused or used only at compile-time.

The only thing there will be a declaration

```Nim
N_LIB_PRIVATE N_NIMCALL(void, nimTestErrorFlag)(void);
```

Example
![image](https://github.com/user-attachments/assets/d946c504-aaca-4a76-bd6b-eafe939b091d)


Counting the number of files with arc/orc vs refc:

![image](https://github.com/user-attachments/assets/2d867a21-87ac-4a2f-9609-bae1fd57f1d4)
