build: Add declaration checks to check for required syscall flags
build: Add declaration checks to check for required syscall flags

The required flags are relatively new and some older enterprise
distributions do not feature them.

https://bugs.freedesktop.org/show_bug.cgi?id=63360

kwm81/weston,jonnylamb/weston,udoprog/weston,Fantu/compositor-spice,krezovic/weston,Tarnyko/weston-xdg_surface_present,mchalupa/weston,Tarnyko/weston-xdg_surface_present,xorgy/weston,krezovic/weston,sir-murray/weston,Fantu/compositor-spice,xorgy/weston,eyolfson/weston,Fantu/compositor-spice,udoprog/weston,kwm81/weston,Gnurou/weston,eyolfson/weston,Gnurou/weston,sir-murray/weston,giucam/weston,jonnylamb/weston,mchalupa/weston,giucam/weston