Make fixes and improvements

- Introduce __assert_disable global
- Improve strsignal() thread safety
- Make system call tracing thread safe
- Fix SO_RCVTIMEO / SO_SNDTIMEO on Windows
- Refactor DescribeFoo() functions into one place
- Fix fork() on Windows when TLS and MAP_STACK exist
- Round upwards in setsockopt(SO_RCVTIMEO) on Windows
- Disable futexes on OpenBSD which seem extremely broken
- Implement a better kludge for monotonic time on Windows

libc/sock/winsockblock.c

@@ -23,7 +23,8 @@
 #include "libc/sock/sock.h"
 #include "libc/str/str.h"
 
-textwindows int64_t __winsockblock(int64_t fh, unsigned eventbit, int64_t rc) {
+textwindows int64_t __winsockblock(int64_t fh, unsigned eventbit, int64_t rc,
+                                   uint32_t timeout) {
   int64_t eh;
   struct NtWsaNetworkEvents ev;
   if (rc != -1) return rc;