rust-cpython: prepare for writing tests that require libpython
What I wanted is to disable the "cpython/extension-module<ver>" feature
while building tests executable, but that seems not doable. Instead,
this patch adds new features dedicated for tests.
The make rule is extracted so that we can easily run cargo tests.
Added a minimal test of ref-sharing as an example. More tests will follow.
$ . "$TESTDIR/narrow-library.sh"
$ hg init repo
$ cd repo
$ cat << EOF > .hg/store/narrowspec
> [include]
> path:foo
> [exclude]
> EOF
$ cp .hg/store/narrowspec .hg/narrowspec.dirstate
$ echo treemanifest >> .hg/requires
$ echo narrowhg-experimental >> .hg/requires
$ mkdir -p foo/bar
$ echo b > foo/f
$ echo c > foo/bar/f
$ hg commit -Am hi
adding foo/bar/f
adding foo/f
$ hg debugindex -m
rev linkrev nodeid p1 p2
0 0 14a5d056d75a 000000000000 000000000000
$ hg debugindex --dir foo
rev linkrev nodeid p1 p2
0 0 e635c7857aef 000000000000 000000000000
$ hg debugindex --dir foo/
rev linkrev nodeid p1 p2
0 0 e635c7857aef 000000000000 000000000000
$ hg debugindex --dir foo/bar
rev linkrev nodeid p1 p2
0 0 e091d4224761 000000000000 000000000000
$ hg debugindex --dir foo/bar/
rev linkrev nodeid p1 p2
0 0 e091d4224761 000000000000 000000000000
$ hg debugdata -m 0
foo\x00e635c7857aef92ac761ce5741a99da159abbbb24t (esc)
$ hg debugdata --dir foo 0
bar\x00e091d42247613adff5d41b67f15fe7189ee97b39t (esc)
f\x001e88685f5ddec574a34c70af492f95b6debc8741 (esc)
$ hg debugdata --dir foo/ 0
bar\x00e091d42247613adff5d41b67f15fe7189ee97b39t (esc)
f\x001e88685f5ddec574a34c70af492f95b6debc8741 (esc)
$ hg debugdata --dir foo/bar 0
f\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)
$ hg debugdata --dir foo/bar/ 0
f\x00149da44f2a4e14f488b7bd4157945a9837408c00 (esc)