Make improvements

- Invent openatemp() API
- Invent O_UNLINK open flag
- Introduce getenv_secure() API
- Remove `git pull` from cosmocc
- Fix utimes() when path is NULL
- Fix mktemp() to never return NULL
- Fix utimensat() UTIME_OMIT on XNU
- Improve utimensat() code for RHEL5
- Turn `argv[0]` C:/ to /C/ on Windows
- Introduce tmpnam() and tmpnam_r() APIs
- Fix more const issues with internal APIs
- Permit utimes() on WIN32 in O_RDONLY mode
- Fix fdopendir() to check fd is a directory
- Fix recent crash regression in landlock make
- Fix futimens(AT_FDCWD, NULL) to return EBADF
- Use workaround so `make -j` doesn't fork bomb
- Rename dontdiscard to __wur (just like glibc)
- Fix st_size for WIN32 symlinks containing UTF-8
- Introduce stdio ext APIs needed by GNU coreutils
- Fix lstat() on WIN32 for symlinks to directories
- Move some constants from normalize.inc to limits.h
- Fix segv with memchr() and memcmp() overlapping page
- Implement POSIX fflush() behavior for reader streams
- Implement AT_SYMLINK_NOFOLLOW for utimensat() on WIN32
- Don't change read-only status of existing files on WIN32
- Correctly handle `0x[^[:xdigit:]]` case in strtol() functions

test/libc/stdio/dirstream_test.c

@@ -25,6 +25,7 @@
 #include "libc/fmt/fmt.h"
 #include "libc/fmt/itoa.h"
 #include "libc/intrin/kprintf.h"
+#include "libc/limits.h"
 #include "libc/mem/critbit0.h"
 #include "libc/mem/gc.h"
 #include "libc/mem/gc.internal.h"
@@ -95,6 +96,13 @@ TEST(opendir, openRealDirEntry) {
   EXPECT_EQ(0, closedir(dir));
 }
 
+TEST(fdopendir, test) {
+  ASSERT_SYS(0, 0, touch("foo", 0644));
+  ASSERT_SYS(0, 3, open("foo", O_RDONLY));
+  ASSERT_SYS(ENOTDIR, 0, fdopendir(3));
+  ASSERT_SYS(0, 0, close(3));
+}
+
 TEST(dirstream, testDots) {
   int hasdot = 0;
   int hasdotdot = 0;