A path whose directory part is a regular file, such as file/child, failed
with ENOENT in open, stat, lstat, access and unlink on Windows, where
FreeBSD 11.4 lookup fails it with ENOTDIR (vfs_cache_lookup, sys/kern/vfs_cache.c).
mkdir and rmdir already did. A not-found error of these calls now asks whether the
nearest existing ancestor is not a directory and reports ENOTDIR then.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>