iter 23.2.2-fixup-doc: tighten try_emit_primitive_instance_body contract doc

crates/ailang-codegen/src/lib.rs

@@ -2441,9 +2441,12 @@ impl<'a> Emitter<'a> {
     /// rather than the `@strcmp + icmp eq i32 0` shape that
     /// `lower_eq`'s Str arm would emit if we let the lambda body
     /// `(== x y)` go through the normal path. Returns `Ok(true)` if
-    /// the body was emitted (caller must return immediately from
-    /// `emit_fn`); `Ok(false)` lets `emit_fn` continue with the
-    /// normal body lowering.
+    /// the body was emitted (including the closing `}` and a final
+    /// `\n\n`); `emit_fn` skips its normal body-lowering branch but
+    /// MUST still run its post-body steps (deferred-thunk flush and
+    /// `emit_adapter_and_static_closure` — the closure-pair every
+    /// top-level fn gets so it is reachable as a `Term::Var` value).
+    /// `Ok(false)` lets `emit_fn` continue with normal body lowering.
     ///
     /// Future iters add `compare__Str` here (23.3); int/bool primitive
     /// methods (`eq__Int`, `eq__Bool`, `compare__Int`, `compare__Bool`)