revlog: add a new test file focussed on testing transactionally issue
What we test here is currently also covered by `test-hooks.t`. However having
our own test file allow for more focussed/deep testing and to cover more variant
when relevant. So we create a new test file.
Differential Revision: https://phab.mercurial-scm.org/D10626
https://bz.mercurial-scm.org/1089
$ hg init
$ mkdir a
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ hg ci -m m a
$ mkdir a b
$ echo a > a/b
$ hg ci -Am m
adding a/b
$ hg rm a
removing a/b
$ cd b
Relative delete:
$ hg ci -m m ../a
$ cd ..