4.9.0 ===== - Fix FSF address and add missing licenses. - Only use -fstack-protector on Linux systems. - Don't use -g3 for full debugging. - Support xldscope for Sun Studio. - Skip -Wredundant-decls on OpenBSD. - Disable --as-needed on OpenBSD (bug #7546). - Use pkg-config macro for detection (bug #7787). - Port exo-csource to xdt-csource (bug #6449).