Use static dispatch for dynamic on Object methods

lib/src/compiler/code_generator.dart

Index: lib/src/compiler/code_generator.dart
diff --git a/lib/src/compiler/code_generator.dart b/lib/src/compiler/code_generator.dart
index 43de895f24bd03427106230beb2078f5d600b6e6..b17ee5b5a1ab26de6a1b68dbffc7b3ce6761d9a8 100644
--- a/lib/src/compiler/code_generator.dart
+++ b/lib/src/compiler/code_generator.dart
@@ -3139,6 +3139,7 @@ class CodeGenerator extends GeneralizingAstVisitor
     // If the target may be an extension type, we also use static dispatch
     // as we don't symbolize object properties like hashCode.
     return isNullable(target) ||
+        type.isDynamic ||
         (_extensionTypes.contains(type.element) && target is! SuperExpression);
   }