Check AI_NUMERICSERV is defined before using it

The AI_NUMERICSERV constant is missing from old Darwin systems, so only
use it if it's supported.

	* include/experimental/internet [AI_NUMERICSERV]
	(resolver_base::numeric_service): Define conditionally.
	* testsuite/experimental/net/internet/resolver/base.cc: Test it
	conditionally.
	* testsuite/experimental/net/internet/resolver/ops/lookup.cc:
	Likewise.

From-SVN: r267809

libstdc++-v3/ChangeLog

+2019-01-10  Jonathan Wakely  <jwakely@redhat.com>
+
+	* include/experimental/internet [AI_NUMERICSERV]
+	(resolver_base::numeric_service): Define conditionally.
+	* testsuite/experimental/net/internet/resolver/base.cc: Test it
+	conditionally.
+	* testsuite/experimental/net/internet/resolver/ops/lookup.cc:
+	Likewise.
+
 2019-01-10  Ville Voutilainen  <ville.voutilainen@gmail.com>
 	    Jonathan Wakely  <jwakely@redhat.com>
 

libstdc++-v3/include/experimental/internet

@@ -1629,7 +1629,9 @@ namespace ip
       __flags_passive			= AI_PASSIVE,
       __flags_canonical_name		= AI_CANONNAME,
       __flags_numeric_host		= AI_NUMERICHOST,
+#ifdef AI_NUMERICSERV
       __flags_numeric_service		= AI_NUMERICSERV,
+#endif
       __flags_v4_mapped			= AI_V4MAPPED,
       __flags_all_matching		= AI_ALL,
       __flags_address_configured	= AI_ADDRCONFIG
@@ -1637,7 +1639,9 @@ namespace ip
     static constexpr flags passive		= __flags_passive;
     static constexpr flags canonical_name	= __flags_canonical_name;
     static constexpr flags numeric_host		= __flags_numeric_host;
+#ifdef AI_NUMERICSERV
     static constexpr flags numeric_service	= __flags_numeric_service;
+#endif
     static constexpr flags v4_mapped		= __flags_v4_mapped;
     static constexpr flags all_matching		= __flags_all_matching;
     static constexpr flags address_configured	= __flags_address_configured;

libstdc++-v3/testsuite/experimental/net/internet/resolver/base.cc

@@ -49,7 +49,9 @@ test01()
   (void) resolver::passive;
   (void) resolver::canonical_name;
   (void) resolver::numeric_host;
+#ifdef AI_NUMERICSERV
   (void) resolver::numeric_service;
+#endif
   (void) resolver::v4_mapped;
   (void) resolver::all_matching;
   (void) resolver::address_configured;

libstdc++-v3/testsuite/experimental/net/internet/resolver/ops/lookup.cc

@@ -49,7 +49,10 @@ test02()
   std::error_code ec;
   io_context ctx;
   ip::tcp::resolver resolv(ctx);
-  auto flags = ip::resolver_base::numeric_host | ip::tcp::resolver::numeric_service;
+  auto flags = ip::resolver_base::numeric_host;
+#ifdef AI_NUMERICSERV
+  flags |= ip::tcp::resolver::numeric_service;
+#endif
   auto addrs = resolv.resolve("127.0.0.1", "42", flags, ec);
   VERIFY( !ec );
   VERIFY( addrs.size() > 0 );