We can't define endpoints and resolvers without the relevant OS support.
If IPPROTO_TCP and IPPROTO_UDP are both undefined then we won't need
basic_endpoint and basic_resolver anyway, so make them depend on those
macros.
libstdc++-v3/ChangeLog:
PR libstdc++/100285
* include/experimental/internet [IPPROTO_TCP || IPPROTO_UDP]
(basic_endpoint, basic_resolver_entry, resolver_base)
(basic_resolver_results, basic_resolver): Only define if the tcp
or udp protocols will be defined.
(cherry picked from commit 793ed718b522b15e2d758eca953feeec1979fe2c)
Jonathan Wakely
132015b9c6