Finish strong mode cleaning of dart2js.

pkg/compiler/lib/src/inferrer/locals_handler.dart

Index: pkg/compiler/lib/src/inferrer/locals_handler.dart
diff --git a/pkg/compiler/lib/src/inferrer/locals_handler.dart b/pkg/compiler/lib/src/inferrer/locals_handler.dart
index 945572fc60fad82b67feee2efd0fcb3f114fac94..e0900e9d2be767414dc6df7442e722931cf7bf8a 100644
--- a/pkg/compiler/lib/src/inferrer/locals_handler.dart
+++ b/pkg/compiler/lib/src/inferrer/locals_handler.dart
@@ -191,6 +191,8 @@ class ArgumentsTypes extends IterableMixin<TypeInformation> {
       if (positional[i] != other.positional[i]) return false;
     }
     named.forEach((name, type) {
+      // Issue 29885.
+      // ignore: RETURN_OF_INVALID_TYPE
       if (other.named[name] != type) return false;
     });
     return true;