In order to have correct code coverage results, we must somehow import
all production modules into the test runner. Until now, this was done
manually (when we didn't forget) in QC.hs.

To improve the situation, we remove QC.hs and replace it with an
auto-generated file which imports all modules. This reduces the
maintenance burden and ensures we'll always have correct coverage.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>