Include netinet/in.h in include/experimental/internet

    2019-09-30  Andreas Tobler  <andreast@gcc.gnu.org>

	* include/experimental/internet: Include netinet/in.h if we have
	_GLIBCXX_HAVE_NETINET_IN_H defined.

From-SVN: r276374

libstdc++-v3/ChangeLog

 2019-09-30  Andreas Tobler  <andreast@gcc.gnu.org>
 
+	* include/experimental/internet: Include netinet/in.h if we have
+	_GLIBCXX_HAVE_NETINET_IN_H defined.
+
 	* testsuite/ext/special_functions/airy_ai/check_nan.cc: Ignore the
 	FreeBSD warning about lower advertised precision of tgammal.
 	* testsuite/ext/special_functions/airy_bi/check_nan.cc: Likewise.

libstdc++-v3/include/experimental/internet

@@ -51,6 +51,9 @@
 #ifdef _GLIBCXX_HAVE_ARPA_INET_H
 # include <arpa/inet.h>		// inet_ntop
 #endif
+#ifdef _GLIBCXX_HAVE_NETINET_IN_H
+# include <netinet/in.h>	// IPPROTO_IP
+#endif
 #ifdef _GLIBCXX_HAVE_NETINET_TCP_H
 # include <netinet/tcp.h>	// TCP_NODELAY
 #endif