wrap call_user_func_array in a wrapper method which optimizes calls with at max 9 args.

on my machine this make things faster.

with the patch
```
php bin/composer update --profile --dry-run
Memory usage: 31.88MB (peak: 57.62MB), time: 7.24s
```

without the patch
```
composer update --profile --dry-run
Memory usage: 31.88MB (peak: 56.62MB), time: 8.13s
```

measured it ~20 times and its roughly 1sec faster including the patch (though peak memory rised 1MB).
I intentionally did not make changes in files which are used by a app at runtime (classloader). Idea was to speedup things for a dev while update/install.

In case you like it we could also add unit-tests.