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

libc/calls/fstatat-nt.c

@@ -34,7 +34,9 @@ textwindows int sys_fstatat_nt(int dirfd, const char *path, struct stat *st,
   uint16_t path16[PATH_MAX];
   if (__mkntpathat(dirfd, path, 0, path16) == -1) return -1;
   if ((fh = CreateFile(
-           path16, kNtFileReadAttributes, 0, 0, kNtOpenExisting,
+           path16, kNtFileReadAttributes,
+           kNtFileShareRead | kNtFileShareWrite | kNtFileShareDelete, 0,
+           kNtOpenExisting,
            kNtFileAttributeNormal | kNtFileFlagBackupSemantics |
                ((flags & AT_SYMLINK_NOFOLLOW) ? kNtFileFlagOpenReparsePoint
                                               : 0),