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/calls/readlinkat_test.c

@@ -20,6 +20,7 @@
 #include "libc/calls/struct/stat.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
+#include "libc/limits.h"
 #include "libc/log/log.h"
 #include "libc/mem/gc.h"
 #include "libc/mem/gc.internal.h"
@@ -96,10 +97,10 @@ TEST(readlinkat, frootloop) {
 
 TEST(readlinkat, statReadsNameLength) {
   struct stat st;
-  ASSERT_SYS(0, 0, symlink("froot", "froot"));
-  ASSERT_SYS(0, 0, fstatat(AT_FDCWD, "froot", &st, AT_SYMLINK_NOFOLLOW));
+  ASSERT_SYS(0, 0, symlink("froÒt", "froÒt"));
+  ASSERT_SYS(0, 0, fstatat(AT_FDCWD, "froÒt", &st, AT_SYMLINK_NOFOLLOW));
   EXPECT_TRUE(S_ISLNK(st.st_mode));
-  EXPECT_EQ(5, st.st_size);
+  EXPECT_EQ(6, st.st_size);
 }
 
 TEST(readlinkat, realpathReturnsLongPath) {