Add MapKeySequence and MapValueSequence classes in core.wren to expose iterable key and value views on Map instances. Implement native iterate_, keyIteratorValue_, and valueIteratorValue_ primitives in wren_core.c to support these sequences. Replace the stub Map.toString with a full implementation that iterates keys and formats each entry as "key: value", handling empty maps and nested maps correctly. Include comprehensive test suites for key iteration, value iteration, iterator type validation, and toString output across multiple orderings.
The Wren scripts in this directory get converted to C string literals and then inserted into their respective .c files so that the interpreter can load them directly without having to do any file IO.
The script that does this copying is script/generate_builtins.py.
You can invoke using make builtin.