26f00ff154
If sets are not enabled, set literals lead to SyntaxError during parsing, so it requires feature_check. Set tests are skipped based on set_*.py pattern.
This directory doesn't contain real tests, but code snippets to detect various interpreter features, which can't be/inconvenient to detecte by other means. Scripts here are executed by run-tests at the beginning of testsuite to decide what other test groups to run/exclude.