Update to GCC copyright assignment policy

[DJ Delorie]

"Maciej W. Rozycki" <macro@orcam.me.uk> writes:
>  My interpretation of this would be for modifications rather than original 
> sources, so v3+ applies to unmodified sources (for obvious reasons, given 
> that the recipient of the sources is not a copyright holder), however as a 
> copyright holder I can release my modifications say under v4 or v4+.  It 
> is unclear to me if the newer licence will then "stick" to the rest of the 
> sources, but I suspect it will.  A copyright assignment made to FSF (or 
> another legal entity) prevents this complication from happening.

I see two cases here:

1. You release a modified copy of gcc, your parts can be whatever you
   want, sure, as long as it's GPLv3 compatible.

2. You're contributing *to* gcc, in which case, I'd hope that any
   attempts to impose a different license would be rejected at the patch
   review step.