bug#51941: Detect duplication of ERT tests

[Lars Ingebrigtsen]

By the way, this reminds me of a different error I often make in ert
files -- I type "defun" instead of "ert-deftest".  Would it be
productive to check whether a -tests.el file contains a defun that's
never called?  In which case it's probably supposed to be en
ert-deftest.

But perhaps it's such a marginal problem that it's not worth checking
for.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no