Make improvements

- Polyfill pselect() on Windows
- Add -O NOFILE flag to pledge.com
- Polyfill ppoll() on NetBSD, XNU, and Windows
- Support negative numbers and errno in sizetol()
- Add .RSS, .NOFILE, and .MAXCORE to Landlock Make
- Fix issue with .PLEDGE preventing touching of output files
- Add __watch() function (like ftrace) for logging memory changes

libc/testlib/testmain.c

@@ -105,7 +105,7 @@ static void EmptySignalMask(void) {
 }
 
 static void FixIrregularFds(void) {
-  int i, fd, maxfds;
+  int e, i, fd, maxfds;
   struct rlimit rlim;
   struct pollfd *pfds;
   for (i = 0; i < 3; ++i) {
@@ -118,6 +118,9 @@ static void FixIrregularFds(void) {
       }
     }
   }
+  e = errno;
+  if (!closefrom(3)) return;
+  errno = e;
   if (IsWindows()) {
     maxfds = 64;
   } else {