tests: add test to show widening is broken without ellipsis This patch adds a test to show that widening a narrow clone is broken if ellipsis is disabled. I don't think I can add cases to existing test-narrow-widen.t and check-in a failing version of that. So I created a copy. Once the test is fixed, we can merge this new test file back into the original one using testcases. Also, this is just testing treemanifest case because having two cases and both or are failing with different outputs is a bit hard to manage. This is important because upcoming patches will try to fix the broken part. Differential Revision: https://phab.mercurial-scm.org/D4382