Fix localhost resolving on windows (#82)

Author: an-tao

trantor/net/InetAddress.cc

@@ -14,7 +14,8 @@
 #ifdef _WIN32
 struct in6_addr_uint
 {
-    union {
+    union
+    {
         u_char Byte[16];
         u_short Word[8];
         uint32_t __s6_addr32[4];

trantor/net/InetAddress.h

@@ -100,7 +100,8 @@ class InetAddress
     }
 
   private:
-    union {
+    union
+    {
         struct sockaddr_in addr_;
         struct sockaddr_in6 addr6_;
     };

trantor/net/inner/AresResolver.cc

@@ -106,6 +106,14 @@ void AresResolver::resolveInLoop(const std::string& hostname,
                                  const Callback& cb)
 {
     loop_->assertInLoopThread();
+#ifdef _WIN32
+    if (hostname == "localhost")
+    {
+        const static trantor::InetAddress localhost_{"127.0.0.1", 0};
+        cb(localhost_);
+        return;
+    }
+#endif
     init();
     QueryData* queryData = new QueryData(this, cb, hostname);
     ares_gethostbyname(ctx_,