Bunch of tests are marked as "passing leak check".
* ab/mark-leak-free-tests:
leak tests: mark some misc tests as passing with SANITIZE=leak
leak tests: mark various "generic" tests as passing with SANITIZE=leak
leak tests: mark some read-tree tests as passing with SANITIZE=leak
leak tests: mark some ls-files tests as passing with SANITIZE=leak
leak tests: mark all checkout-index tests as passing with SANITIZE=leak
leak tests: mark all trace2 tests as passing with SANITIZE=leak
leak tests: mark all ls-tree tests as passing with SANITIZE=leak
leak tests: run various "test-tool" tests in t00*.sh SANITIZE=leak
leak tests: run various built-in tests in t00*.sh SANITIZE=leak