Fast alist mapping file names to T.
This is a cache for speeding up direct file name lookups by
avoiding repeated filesystem access. It is suitable for `include files
where we know the entire filename.
- Recognizer for vl-dircache.
- (vl-dircache-fix x) is an fty alist fixing function that follows the fix-keys strategy.
- Make a vl-dircache for a directory.
- Basic equivalence relation for vl-dircache structures.