dirstate: Removed unused instances of `DirsMultiset`...
dirstate: Removed unused instances of `DirsMultiset`
… in Rust-backed dirstatemap.
The Python class `dirstatemap` had cached properties `_dirs` and `_alldirs`
that were not used for `hastrackeddir` and `hasdir` since they were redundant
with corresponding fields for the Rust `DirstateMap` struct.
`dirfoldmap` is modified to reuse instead the directory iterator introduced
in 3b9914b28133c0918186b6e8b9e4f1916e21338d.
Differential Revision:
https://phab.mercurial-scm.org/D10921
