[patch] copyright notice correction on libiberty/make-relative-prefix.c

[Nathanael Nerode]

DJ Delorie wrote:
>>Only edits in CVS history are by drow, dannysmith, and nickc (and
>>the latter two are miniscule, probably not copyrightable).
> 
> Except the function was originally added by Mike Meissner.

As part of gcc.c.

Most of the substantive work on the function was done while it was in 
the gcc/ directory, and the people doing the work presumably had gcc 
copyright assignments, unless some sort of legal mistakes were being 
made way back then.

The current notice is *broken*; it doesn't assert a license on its own 
file.  I'll put in whatever internally consistent version is believed to 
be most legally correct.  I have stated my reasons for believing that 
"part of GCC" is correct provided drow has a GCC assignment (I'm pretty 
sure he does).

--Nathanael