Allow running test in uninstalled source tree.

It was pointed out that we missed the use-case that running tests
in a fresh tree checkout should work - and we missed that by
reaching too far into the setup module interface. Shame on us.

Change-Id: Ic0056a3113b308f063d927484e1e4a44c9316a2d
Merge "Allow running test in uninstalled source tree."