Expand description
method_returns salsa query — derives the per-file map of
class_name -> method_name -> return_class_name. Depends on parsed_doc.
This is the sole cache for method-return inference since Phase E3 removed
the OnceLock<MethodReturnsMap> from ParsedDoc. Production call sites
(inlay_hints, type_definition, hover, completion) fetch the memoized
Arc<MethodReturnsMap> via DocumentStore::get_method_returns_salsa /
other_docs_with_returns and pass it into the TypeMap constructors.