devel/cdecl: update to 7.4.

Bison debugging change
Changed --enable--yydebug configure option to --enable-bison-debug, --yydebug/-y cdecl options to --bison-debug/-B, and yydebug to bison-debug set option.

Added Flex debugging
Added --enable-flex-debug configure option, --flex-debug/-F cdecl options, and flex-debug set option.

Fixed set options
Finally fixed parsing of set options.