Make improvements

- Introduce ualarm() function
- Make rename() report EISEMPTY on Windows
- Always raise EINVAL upon open(O_RDONLY|O_TRUNC)
- Add macro so ./configure will detect SOCK_CLOEXEC
- Fix O_TRUNC without O_CREAT not working on Windows
- Let fcntl(F_SETFL) change O_APPEND status on Windows
- Make sure pwrite() / pread() report ESPIPE on sockets
- Raise ESPIPE on Windows when pwrite() is used on pipe
- Properly compute O_APPEND CreateFile() flags on Windows
- Don't require O_DIRECTORY to open directories on Windows
- Fix more instances of Windows reporting EISDIR and ENOTDIR
- Normalize EFTYPE and EMLINK to ELOOP on NetBSD and FreeBSD
- Make unlink() / rmdir() work on read-only files on Windows
- Validate UTF-8 on Windows paths to fix bug with overlong NUL
- Always print signal name to stderr when crashing due to SIG_DFL
- Fix Windows bug where denormalized paths >260 chars didn't work
- Block signals on BSDs when thread exits before trashing its own stack

libc/calls/posix_fadvise.c

@@ -18,6 +18,8 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/assert.h"
 #include "libc/calls/calls.h"
+#include "libc/calls/internal.h"
+#include "libc/calls/struct/fd.internal.h"
 #include "libc/calls/syscall-nt.internal.h"
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
@@ -41,13 +43,16 @@ int sys_fadvise_netbsd(int, int, int64_t, int64_t, int) asm("sys_fadvise");
  * @raise EBADF if `fd` isn't a valid file descriptor
  * @raise EINVAL if `advice` is invalid or `len` is huge
  * @raise ESPIPE if `fd` refers to a pipe
+ * @raise ENOTSUP if `fd` is a /zip file
  * @raise ENOSYS on XNU and OpenBSD
  * @returnserrno
  * @threadsafe
  */
 errno_t posix_fadvise(int fd, int64_t offset, int64_t len, int advice) {
   int rc, e = errno;
-  if (IsLinux()) {
+  if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
+    rc = enotsup();
+  } else if (IsLinux()) {
     rc = sys_fadvise(fd, offset, len, advice);
   } else if (IsFreebsd()) {
     rc = sys_fadvise(fd, offset, len, advice);