test: avoid in6addr_* constants

These aren't available on MinGW, so use explicit addresses instead.

test/ares-test-live.cc

@@ -157,7 +157,9 @@ TEST_P(DefaultChannelModeTest, LiveGetLocalhostByAddrV4) {
 
 TEST_P(DefaultChannelModeTest, LiveGetLocalhostByAddrV6) {
   HostResult result;
-  struct in6_addr addr = in6addr_loopback;
+  struct in6_addr addr;
+  memset(&addr, 0, sizeof(addr));
+  addr.s6_addr[15] = 1;  // in6addr_loopback
   ares_gethostbyaddr(channel_, &addr, sizeof(addr), AF_INET6, HostCallback, &result);
   Process();
   EXPECT_TRUE(result.done_);

test/ares-test.cc

@@ -180,7 +180,7 @@ MockServer::MockServer(int family, int port, int tcpport)
     struct sockaddr_in6 addr;
     memset(&addr, 0, sizeof(addr));
     addr.sin6_family = AF_INET6;
-    addr.sin6_addr = in6addr_any;
+    memset(&addr.sin6_addr, 0, sizeof(addr.sin6_addr));  // in6addr_any
     addr.sin6_port = htons(tcpport_);
     int tcprc = bind(tcpfd_, (struct sockaddr*)&addr, sizeof(addr));
     EXPECT_EQ(0, tcprc) << "Failed to bind AF_INET6 to TCP port " << tcpport_;