[ocamlbuild] Add some more tests for PR#4592 and PR#5752.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13272 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02
[ocamlbuild] Real time update of the tests, by flushing the channel after each test result.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@13273 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02