4.2 Project: "@file" support

[Laurent GUERBY]

If we add a library function to handle this we might want to
add a GNU-style argument equivalent like

gcc --arguments-from-file=file

Which would be equivalent to:

gcc @file

May be some GNU tools already have standardized on a long
argument name for such a feature, but none came to my mind
(and I'm not that proud of my proposed name :).

Laurent

PS: removed gcc-patches