eac78f28c1
Add Iter_Map<T,U>, Filter, Fold, Any, All, ForEach over fat function pointers; keep Iter_MapInt and friends as thin aliases. Compiler fixes required for non-int returns and capturing closures: - bootstrap: resolve fat-func call return type under mono typeSubst - bootstrap: type-check args of Foo<T>(...) so closures capture correctly - selfhost: substitute type params inside tekFunc (BuxFn_U_T → concrete) - selfhost: emit cstr fat typedefs with #ifndef redefinition guards Example: examples/iter_generic.bux (int↔String map, fold, closures). Selfhost-loop remains binary-identical.