Don't evaluate << because of possible overflow.

pkg/analyzer_experimental/lib/src/generated/resolver.dart

Index: pkg/analyzer_experimental/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer_experimental/lib/src/generated/resolver.dart b/pkg/analyzer_experimental/lib/src/generated/resolver.dart
index 33b7305592e5fb400011ace2263f97aa367f7815..0ff54abf0c4259d2f1cd1d32c52ba24e663aa90f 100644
--- a/pkg/analyzer_experimental/lib/src/generated/resolver.dart
+++ b/pkg/analyzer_experimental/lib/src/generated/resolver.dart
@@ -12593,6 +12593,7 @@ class ErrorVerifier extends RecursiveASTVisitor<Object> {
       checkForDuplicateDefinitionInheritance();
       checkForConflictingGetterAndMethod();
       checkImplementsSuperClass(node);
+      checkImplementsFunctionWithoutCall(node);
       return super.visitClassDeclaration(node);
     } finally {
       _isInNativeClass = false;
@@ -16195,6 +16196,32 @@ class ErrorVerifier extends RecursiveASTVisitor<Object> {
   }
 
   /**
+   * This verifies that if the given class declaration implements the class Function that it has a
+   * concrete implementation of the call method.
+   *
+   * @return `true` if and only if an error code is generated on the passed node
+   * @see StaticWarningCode#FUNCTION_WITHOUT_CALL
+   */
+  bool checkImplementsFunctionWithoutCall(ClassDeclaration node) {
+    if (node.abstractKeyword != null) {
+      return false;
+    }
+    ClassElement classElement = node.element;
+    if (classElement == null) {
+      return false;
+    }
+    if (!classElement.type.isSubtypeOf(_typeProvider.functionType)) {
+      return false;
+    }
+    ExecutableElement callMethod = _inheritanceManager.lookupMember(classElement, "call");
+    if (callMethod == null || callMethod is! MethodElement || ((callMethod as MethodElement)).isAbstract) {
+      _errorReporter.reportError2(StaticWarningCode.FUNCTION_WITHOUT_CALL, node.name, []);
+      return true;
+    }
+    return false;
+  }
+
+  /**
    * This verifies that the given class declaration does not have the same class in the 'extends'
    * and 'implements' clauses.
    *