Fix known_node_failures: 4500, VTAsClassHeads, Rank2TypeSynonym, Deriving*, 3957, and partial TCOMutRec

Major changes:
- Fix VTA constraint deferral for non-class-method functions (infer.rs)
- Add Reflectable compiler-magic type resolution in Pass 2.8 (check.rs)
- Add method_own_constraint_details to ModuleExports for cross-module import
- Implement return-type dict param tracking (used_return_type_dicts) in codegen
- Add mutual recursion inlining for TCO (inline where-bound functions to enable
  self-recursion detection), with Direction 1 (inline callee into caller) and
  Direction 2 (inline caller into callee via variable substitution)
- Apply TCO to nested where-bound functions that are already self-recursive
- Remove 3957, 4500, DerivingFoldable, DerivingFunctor, DerivingTraversable,
  Rank2TypeSynonym, VTAsClassHeads from known_node_failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: roryc89

src/build/portable.rs

@@ -442,6 +442,7 @@ impl PModuleExports {
             method_own_constraints: self.method_own_constraints.iter().map(|(k, v)| {
                 (rest_qi(k, st), v.iter().map(|s| st.sym(*s)).collect())
             }).collect(),
+            method_own_constraint_details: std::collections::HashMap::new(), // not persisted in portable format yet
             module_doc: Vec::new(), // not persisted in portable format
             instance_registry: self.instance_registry.iter().map(|((class, head), inst)| {
                 ((st.sym(*class), st.sym(*head)), st.sym(*inst))