Add epoll and do more release readiness changes

This change also pays off some of the remaining technical debt with
stdio, file descriptors, and memory managemnt polyfills.

libc/nt/enum/afd.h

@@ -0,0 +1,13 @@
+#ifndef COSMOPOLITAN_LIBC_NT_ENUM_AFD_H_
+#define COSMOPOLITAN_LIBC_NT_ENUM_AFD_H_
+
+#define kNtAfdPollReceive          0x0001
+#define kNtAfdPollReceiveExpedited 0x0002
+#define kNtAfdPollSend             0x0004
+#define kNtAfdPollDisconnect       0x0008
+#define kNtAfdPollAbort            0x0010
+#define kNtAfdPollLocalClose       0x0020
+#define kNtAfdPollAccept           0x0080
+#define kNtAfdPollConnectFail      0x0100
+
+#endif /* COSMOPOLITAN_LIBC_NT_ENUM_AFD_H_ */