Have config_sspi_auth() permit IPv6 localhost connections.

Windows versions later than Windows Server 2003 map "localhost" to ::1.
Account for that in the generated pg_hba.conf, fixing another oversight
in commit f6dc6dd5ba.  Back-patch to 9.0,
like that commit.

David Rowley and Noah Misch

src/test/regress/pg_regress.c

@@ -1048,6 +1048,7 @@ config_sspi_auth(const char *pgdata)
 			   *domainname;
 	char		username[128];
 	DWORD		sz = sizeof(username) - 1;
+	bool		have_ipv6;
 	char		fname[MAXPGPATH];
 	int			res;
 	FILE	   *hba,
@@ -1067,6 +1068,28 @@ config_sspi_auth(const char *pgdata)
 		exit(2);
 	}
 
+	/*
+	 * Like initdb.c:setup_config(), determine whether the platform recognizes
+	 * ::1 (IPv6 loopback) as a numeric host address string.
+	 */
+	{
+		struct addrinfo *gai_result;
+		struct addrinfo hints;
+		WSADATA		wsaData;
+
+		hints.ai_flags = AI_NUMERICHOST;
+		hints.ai_family = AF_UNSPEC;
+		hints.ai_socktype = 0;
+		hints.ai_protocol = 0;
+		hints.ai_addrlen = 0;
+		hints.ai_canonname = NULL;
+		hints.ai_addr = NULL;
+		hints.ai_next = NULL;
+
+		have_ipv6 = (WSAStartup(MAKEWORD(2, 2), &wsaData) == 0 &&
+					 getaddrinfo("::1", NULL, &hints, &gai_result) == 0);
+	}
+
 	/* Check a Write outcome and report any error. */
 #define CW(cond)	\
 	do { \
@@ -1098,6 +1121,9 @@ config_sspi_auth(const char *pgdata)
 	CW(fputs("# Configuration written by config_sspi_auth()\n", hba) >= 0);
 	CW(fputs("host all all 127.0.0.1/32  sspi include_realm=1 map=regress\n",
 			 hba) >= 0);
+	if (have_ipv6)
+		CW(fputs("host all all ::1/128  sspi include_realm=1 map=regress\n",
+				 hba) >= 0);
 	CW(fclose(hba) == 0);
 
 	snprintf(fname, sizeof(fname), "%s/pg_ident.conf", pgdata);

src/tools/msvc/Mkvcbuild.pm

@@ -272,6 +272,7 @@ sub mkvcbuild
     $pgregress_ecpg->AddIncludeDir('src\test\regress');
     $pgregress_ecpg->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
     $pgregress_ecpg->AddDefine('FRONTEND');
+    $pgregress_ecpg->AddLibrary('ws2_32.lib');
     $pgregress_ecpg->AddReference($libpgport);
 
     my $isolation_tester = $solution->AddProject('isolationtester','exe','misc');
@@ -294,6 +295,7 @@ sub mkvcbuild
     $pgregress_isolation->AddIncludeDir('src\test\regress');
     $pgregress_isolation->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
     $pgregress_isolation->AddDefine('FRONTEND');
+    $pgregress_isolation->AddLibrary('ws2_32.lib');
     $pgregress_isolation->AddReference($libpgport);
 
     # src/bin
@@ -486,6 +488,8 @@ sub mkvcbuild
     $pgregress->AddFile('src\test\regress\pg_regress_main.c');
     $pgregress->AddIncludeDir('src\port');
     $pgregress->AddDefine('HOST_TUPLE="i686-pc-win32vc"');
+    $pgregress->AddDefine('FRONTEND');
+    $pgregress->AddLibrary('ws2_32.lib');
     $pgregress->AddReference($libpgport);
 
     $solution->Save();