GCC Linking exception to GPL 2.0 or later

GCC Linking Exception
In addition to the permissions in the GNU General Public License, the Free
Software Foundation gives you unlimited permission to link the compiled version
of this file into combinations with other programs, and to distribute those
combinations without any restriction coming from the use of this file. 
(The General Public License restrictions do apply in other respects; for
example, they cover modification of the file, and distribution when not linked
into a combined executable.