All (or almost all?) tests currently in crates/red_knot_python_semantic/src/types/infer.rs should be ported to the new test framework (that is, to Markdown files in crates/red_knot_python_semantic/resources/mdtest/ directory.)

Documentation of the new test framework is in crates/red_knot_test/README.md (or will be once #13695 lands.)

Generally we should try to group closely-related tests in the same Markdown file, but avoid having any one file become too large.

Some tests in infer.rs will require features we haven't added to the test framework yet. Those can be left alone for now (or we can add the feature to the test framework!)

Please comment here before starting work on any test porting, to avoid duplicated work.