F21 system GCC changed to 4.9.0 prerelease

[Jakub Jelinek]

Hi!

FYI, gcc in rawhide has been upgraded to 4.9.0 prerelease,
please visit http://gcc.gnu.org/gcc-4.9/porting_to.html if your
package no longer builds.  To investigate runtime rather than compile time
issues, please consider using temporarily -fsanitize=undefined and/or
-fsanitize=address to look for undefined behavior in the packages
you own.

	Jakub