testrunner: make reading of test times work with #testcases
Due to a bug that will be fixed in the next patch, we never actually
read back .testcases, so we didn't notice that it could not be parsed
successfully when there are #testcases tests. The parsing failed on
lines like "test-amend-subrepo.t (case obsstore-off) 32.420" because
we used a simple string.split() call and expected all parts but the
first to be floating point numbers (and "(case" isn't, for
example). Fix by using a regex instead.
Differential Revision: https://phab.mercurial-scm.org/D1960
Run Mercurial tests with Vagrant:
$ vagrant up
$ vagrant ssh -c ./run-tests.sh