rust-dirstate: call rust dirstatemap from Python
Since Rust-backed Python classes cannot be used as baseclasses (for
rust-cpython anyway), we use composition rather than inheritance.
This also allows us to keep the IO operations in the Python side, removing
(for now) the need to rewrite VFS in Rust, which would be a heavy undertaking.
Differential Revision: https://phab.mercurial-scm.org/D6634
#require docutils gettext
Error: the current ro localization has some rst defects exposed by
moving pager to core. These two warnings about references are expected
until the localization is corrected.
$ $TESTDIR/check-gendoc ro
checking for parse errors
gendoc.txt:58: (WARNING/2) Inline interpreted text or phrase reference start-string without end-string.
gendoc.txt:58: (WARNING/2) Inline interpreted text or phrase reference start-string without end-string.