match: fix the rust-side bug in visit_children_set for rootfilesin matchers
The fix is checked by `test_pattern_matcher_visit_children_set` test,
which is what caught the bug in the first place, but also by an end-to-end
test that I made for this purpose.
Accept the new results of Cargo tests
Many of these were already annotated with "FIXME", which is a good sign.
$ hg init repo
$ cd repo
$ echo a > a
$ hg ci -Am t
adding a
$ hg mv a b
$ hg ci -Am t1
$ hg debugrename b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
$ hg mv b a
$ hg ci -Am t2
$ hg debugrename a
a renamed from b:37d9b5d994eab34eda9c16b195ace52c7b129980
$ hg debugrename --rev 1 b
b renamed from a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3