Improve system call support on NT

- Improve i/o perf on New Technology
- Code cleanup on read() for New Technology
- Fix bad bug with dup() of socket on New Technology
- Clean up some more strace errors on New Technology

libc/calls/fstatat.c

@@ -22,20 +22,29 @@
 #include "libc/calls/strace.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
+#include "libc/fmt/itoa.h"
 #include "libc/intrin/asan.internal.h"
+#include "libc/intrin/kprintf.h"
 #include "libc/log/log.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/at.h"
 #include "libc/sysv/errfuns.h"
 #include "libc/zipos/zipos.internal.h"
 
+static inline const char *__strace_fstatat_flags(int flags) {
+  static char buf[12];
+  if (flags == AT_SYMLINK_NOFOLLOW) return "AT_SYMLINK_NOFOLLOW";
+  FormatInt32(buf, flags);
+  return buf;
+}
+
 /**
  * Returns information about thing.
  *
  * @param dirfd is normally AT_FDCWD but if it's an open directory and
  *     file is a relative path, then file becomes relative to dirfd
  * @param st is where result is stored
- * @param flags can have AT_{EMPTY_PATH,NO_AUTOMOUNT,SYMLINK_NOFOLLOW}
+ * @param flags can have AT_SYMLINK_NOFOLLOW
  * @return 0 on success, or -1 w/ errno
  * @see S_ISDIR(st.st_mode), S_ISREG()
  * @asyncsignalsafe
@@ -44,6 +53,7 @@
 int fstatat(int dirfd, const char *path, struct stat *st, int flags) {
   /* execve() depends on this */
   int rc;
+  char buf[12];
   struct ZiposUri zipname;
   if (__isfdkind(dirfd, kFdZip)) {
     STRACE("zipos dirfd not supported yet");
@@ -60,7 +70,7 @@ int fstatat(int dirfd, const char *path, struct stat *st, int flags) {
   } else {
     rc = sys_fstatat_nt(dirfd, path, st, flags);
   }
-  STRACE("fstatat(%d, %#s, [%s], %#b) → %d% m", dirfd, path,
-         __strace_stat(rc, st), flags, rc);
+  STRACE("fstatat(%s, %#s, [%s], %s) → %d% m", __strace_dirfd(buf, dirfd), path,
+         __strace_stat(rc, st), __strace_fstatat_flags(flags), rc);
   return rc;
 }