[distcc] ccache doesn't handle .i files

[eezyy at gmx.net]

   > +	} else {
   > +		copy_file(input_file, path_stdout);
   > +		x_asprintf(&command, "touch %s", path_stderr);
   > +		system(command);
   > +		free(command);
   > +	}

   Huh?

i know, it's been a while since i last did c. i'm sure there are
faster ways to provide the empty preprocessor error file, or maybe
it's not even needed if the hashing gets moved into the
conditional. i was just curious if it would be that hard to get it to
work, and it seemed to do when i tested it locally.

isidor