Don't call dinvoke on Object methods

lib/src/checker/checker.dart

Index: lib/src/checker/checker.dart
diff --git a/lib/src/checker/checker.dart b/lib/src/checker/checker.dart
index 024a066ca63de43dfab84015068e927b21c4657c..1dd4eb825a15a2c900554a7b72e9d0c831de0699 100644
--- a/lib/src/checker/checker.dart
+++ b/lib/src/checker/checker.dart
@@ -566,7 +566,8 @@ class CodeChecker extends RecursiveAstVisitor {
   }
 
   visitPropertyAccess(PropertyAccess node) {
-    if (_rules.isDynamicGet(node.realTarget)) {
+    if (node.staticType.isDynamic &&
+        _rules.isDynamicGet(node.realTarget, node.propertyName)) {
       _recordDynamicInvoke(node);
     }
     node.visitChildren(this);
@@ -576,7 +577,8 @@ class CodeChecker extends RecursiveAstVisitor {
     final target = node.prefix;
     // Check if the prefix is a library - PrefixElement denotes a library
     // access.
-    if (target.staticElement is! PrefixElement && _rules.isDynamicGet(target)) {
+    if (target.staticElement is! PrefixElement &&
+        _rules.isDynamicGet(target, node.identifier)) {
       _recordDynamicInvoke(node);
     }
     node.visitChildren(this);