index: create function for deleting node from nodetree
A node is marked deleted by nt_insert(self, node, -1), but "-1" could
mean so many things (notably nullrev), so let's hide it in a
function. The function could possibly also remove nodes from the tree
in the future (it currently only marks them deleted).
Differential Revision: https://phab.mercurial-scm.org/D4004
running: init test1
result: 0
running: add foo
result: 0
running: commit -m commit1 -d 2000-01-01 foo
result: 0
running: commit -m commit2 -d 2000-01-02 foo
result: 0
running: log -r 0
changeset: 0:0e4634943879
user: test
date: Sat Jan 01 00:00:00 2000 +0000
summary: commit1
result: 0
running: log -r tip
changeset: 1:45589e459b2e
tag: tip
user: test
date: Sun Jan 02 00:00:00 2000 +0000
summary: commit2
result: 0