Add Windows WSAPool declaration, associated struct and constants. It allows 100% poll compatible POSIX API on Windows.

win32/include/winapi/winsock2.h

@@ -1428,6 +1428,29 @@ extern "C" {
 #define WSAGETSELECTEVENT(lParam) LOWORD(lParam)
 #define WSAGETSELECTERROR(lParam) HIWORD(lParam)
 
+/* #if (_WIN32_WINNT >= 0x0600) */
+#define POLLRDNORM  0x0100
+#define POLLRDBAND  0x0200
+#define POLLIN      (POLLRDNORM | POLLRDBAND)
+#define POLLPRI     0x0400
+
+#define POLLWRNORM  0x0010
+#define POLLOUT     (POLLWRNORM)
+#define POLLWRBAND  0x0020
+
+#define POLLERR     0x0001
+#define POLLHUP     0x0002
+#define POLLNVAL    0x0004
+
+typedef struct pollfd {
+        SOCKET fd;
+        SHORT  events;
+        SHORT  revents;
+} WSAPOLLFD, *PWSAPOLLFD, FAR *LPWSAPOLLFD;
+
+WINSOCK_API_LINKAGE int WSAAPI WSAPoll(LPWSAPOLLFD fdArray, ULONG fds, INT timeout);
+/* #endif // (_WIN32_WINNT >= 0x0600) */
+
 #ifdef __cplusplus
 }
 #endif