## Summary Another follow-up to the unions-of-large-literals optimization. Restore the behavior that e.g. `Literal[""] | ~Literal[""]` collapses to `object`. ## Test Plan Added mdtests.
Markdown files within the mdtest/ subdirectory are tests of type inference and type checking;
executed by the tests/mdtest.rs integration test.
See crates/red_knot_test/README.md for documentation of this test format.