include ast_checks in code coverage

ast checks are newer, but they both handle parsing as well as validating
what was parsed, so they are even superior to regular pass checks.

Thus they should also be included in the coverage output.

Author: WebFreak001

test/run_tests.sh

@@ -101,7 +101,7 @@ echo
 find . -name "*.lst" -exec rm -f {} \;
 echo -en "Generating coverage reports... "
 ${DMD} tester.d -cov -unittest $SOURCE_FILES $IMPORT_PATHS
-./tester --ast --DRT-testmode=run-main $PASS_FILES $FAIL_FILES &> /dev/null || true
+./tester --ast --DRT-testmode=run-main $PASS_FILES $FAIL_FILES ast_checks/*.d &> /dev/null || true
 rm -rf coverage/
 mkdir coverage/
 find . -name "*.lst" | while read -r i; do