By: Tom Sydney Kerckhove <syd@cs-syd.eu>
Add includeTests option to makeWeederCheck (default false)
By default, makeWeederCheck no longer feeds weeder the test suites' .hie
files: it skips buildTestsWithoutRunning, so code used only by tests is
reported as a weed ("don't keep code alive purely by testing it").
Set includeTests = true to restore the previous behavior (compile the test
code without running it and include its .hie files), which prevents
false-positives for code that exists only to be tested.
Note: with includeTests = false the only roots are those in weeder.toml; a
library whose public API is exercised only by its own tests needs those
modules declared as roots.