Add windows bindings to support overlapped IO

core/sys/windows/kernel32.odin

@@ -372,6 +372,12 @@ foreign kernel32 {
 		bInitialState: BOOL,
 		lpName: LPCWSTR,
 	) -> HANDLE ---
+	CreateEventExW :: proc(
+		lpEventAttributes: LPSECURITY_ATTRIBUTES,
+		lpName: LPCWSTR,
+		dwFlags: DWORD,
+		dwDesiredAccess: DWORD,
+	) -> HANDLE ---
 	ResetEvent :: proc(hEvent: HANDLE) -> BOOL ---
 	SetEvent :: proc(hEvent: HANDLE) -> BOOL ---
 	WaitForMultipleObjects :: proc(

core/sys/windows/types.odin

@@ -4845,6 +4845,12 @@ SOMAXCONN    :: 128 // The number of messages that can be queued in memory after
 SOCKET_ERROR :: -1
 
 // Networking errors
+WSA_INVALID_HANDLE     :: 6     // Specified event object handle is invalid.
+WSA_NOT_ENOUGH_MEMORY  :: 8     // Insufficient memory available.
+WSA_INVALID_PARAMETER  :: 87    // One or more parameters are invalid.
+WSA_OPERATION_ABORTED  :: 995   // Overlapped operation aborted.
+WSA_IO_INCOMPLETE      :: 996   // Overlapped I/O event object not in signaled state.
+WSA_IO_PENDING         :: 997   // Overlapped operations will complete later.
 WSAEINTR               :: 10004 // Call interrupted. CancelBlockingCall was called. (This is different on Linux.)
 WSAEACCES              :: 10013 // If you try to bind a Udp socket to the broadcast address without the socket option set.
 WSAEFAULT              :: 10014 // A pointer that was passed to a WSA function is invalid, such as a buffer size is smaller than you said it was

core/sys/windows/ws2_32.odin

@@ -131,6 +131,10 @@ foreign ws2_32 {
 	) -> SOCKET ---
 	// [MS-Docs](https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsaioctl)
 	WSAIoctl :: proc(s: SOCKET, dwIoControlCode: DWORD, lpvInBuffer: rawptr, cbInBuffer: DWORD, lpvOutBuffer: rawptr, cbOutBuffer: DWORD, lpcbBytesReturned: ^DWORD, lpOverlapped: ^OVERLAPPED, lpCompletionRoutine: LPWSAOVERLAPPED_COMPLETION_ROUTINE) -> c_int ---
+	// [MS-Docs](https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsacreateevent)
+	WSACreateEvent :: proc() -> WSAEVENT ---
+	// [MS-Docs](https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsacloseevent)
+	WSACloseEvent :: proc(hEvent: WSAEVENT) -> bool ---
 	// [MS-Docs](https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsaeventselect)
 	WSAEventSelect :: proc(s: SOCKET, hEventObject: WSAEVENT, lNetworkEvents: i32) -> c_int ---
 	// [MS-Docs](https://learn.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-wsawaitformultipleevents)