Fixes #13893 - some standard library networking tests are failing on Windows

Author: binarycraft007

lib/std/os/windows.zig

@@ -2068,7 +2068,7 @@ pub fn loadWinsockExtensionFunction(comptime T: type, sock: ws2_32.SOCKET, guid:
         ws2_32.SIO_GET_EXTENSION_FUNCTION_POINTER,
         @ptrCast(*const anyopaque, &guid),
         @sizeOf(GUID),
-        @intToPtr(?*anyopaque, @ptrToInt(function)),
+        @intToPtr(?*anyopaque, @ptrToInt(&function)),
         @sizeOf(T),
         &num_bytes,
         null,

lib/std/os/windows/test.zig

@@ -63,3 +63,28 @@ test "removeDotDirs" {
     try testRemoveDotDirs("a\\b\\..\\", "a\\");
     try testRemoveDotDirs("a\\b\\..\\c", "a\\c");
 }
+
+test "loadWinsockExtensionFunction" {
+    _ = try windows.WSAStartup(2, 2);
+    defer windows.WSACleanup() catch unreachable;
+
+    const LPFN_CONNECTEX = *const fn (
+        Socket: windows.ws2_32.SOCKET,
+        SockAddr: *const windows.ws2_32.sockaddr,
+        SockLen: std.os.socklen_t,
+        SendBuf: ?*const anyopaque,
+        SendBufLen: windows.DWORD,
+        BytesSent: *windows.DWORD,
+        Overlapped: *windows.OVERLAPPED,
+    ) callconv(windows.WINAPI) windows.BOOL;
+
+    _ = windows.loadWinsockExtensionFunction(
+        LPFN_CONNECTEX,
+        try std.os.socket(std.os.AF.INET, std.os.SOCK.DGRAM, 0),
+        windows.ws2_32.WSAID_CONNECTEX,
+    ) catch |err| switch (err) {
+        error.OperationNotSupported => unreachable,
+        error.ShortRead => unreachable,
+        else => |e| return e,
+    };
+}