configure.ac : When compiling with GCC use some extra warning flags.
configure.ac : When compiling with GCC use some extra warning flags.

fredericgermain/flac,waitman/flac,waitman/flac,Distrotech/flac,fredericgermain/flac,fredericgermain/flac,Distrotech/flac,LordJZ/libflac,Distrotech/flac,LordJZ/libflac,waitman/flac,fredericgermain/flac,Distrotech/flac,waitman/flac,LordJZ/libflac,LordJZ/libflac,waitman/flac