Don't call dinvoke on Object methods

lib/src/checker/rules.dart

Index: lib/src/checker/rules.dart
diff --git a/lib/src/checker/rules.dart b/lib/src/checker/rules.dart
index ef09d3b871cb37a522590947b52d22e2cb31f900..b1d313b585b7bd689c4ed652216a824dd6872201 100644
--- a/lib/src/checker/rules.dart
+++ b/lib/src/checker/rules.dart
@@ -44,7 +44,7 @@ abstract class TypeRules {
 
   bool isDynamic(DartType t);
   bool isDynamicTarget(Expression expr);
-  bool isDynamicGet(Expression expr);
+  bool isDynamicGet(Expression target, SimpleIdentifier name);
   bool isDynamicCall(Expression call);
 }
 
@@ -75,7 +75,7 @@ class DartRules extends TypeRules {
   /// By default, all invocations are dynamic in Dart.
   bool isDynamic(DartType t) => true;
   bool isDynamicTarget(Expression expr) => true;
-  bool isDynamicGet(Expression expr) => true;
+  bool isDynamicGet(Expression target, SimpleIdentifier name) => true;
   bool isDynamicCall(Expression call) => true;
 }
 
@@ -530,9 +530,10 @@ class RestrictedRules extends TypeRules {
 
   /// Returns `true` if the expression is a dynamic property access or prefixed
   /// identifier.
-  bool isDynamicGet(Expression expr) {
+  bool isDynamicGet(Expression target, SimpleIdentifier name) {
     if (options.ignoreTypes) return true;
-    var t = getStaticType(expr);
+    if (!name.staticType.isDynamic) return false;
+    var t = getStaticType(target);
     // TODO(jmesserly): we should not allow all property gets on `Function`
     return t.isDynamic || t.isDartCoreFunction;
   }