Add support for GLIB_DEPRECATED_ decorators

Examples:

G_SPAWN_ERROR_2BIG GLIB_DEPRECATED_ENUMERATOR_IN_2_32_FOR(G_SPAWN_ERROR_TOO_BIG) = G_SPAWN_ERROR_TOO_BIG,
} GTestTrapFlags GLIB_DEPRECATED_TYPE_IN_2_38_FOR(GTestSubprocessFlags);