Handle assignability for Send and SendSet

sdk/lib/_internal/compiler/implementation/warnings.dart

Index: sdk/lib/_internal/compiler/implementation/warnings.dart
diff --git a/sdk/lib/_internal/compiler/implementation/warnings.dart b/sdk/lib/_internal/compiler/implementation/warnings.dart
index 7dcebd8a97a448255fd16cf5d9496ba86e188875..c609c17d1d1a07a8b57bc56e847a4b0cad360dbb 100644
--- a/sdk/lib/_internal/compiler/implementation/warnings.dart
+++ b/sdk/lib/_internal/compiler/implementation/warnings.dart
@@ -28,6 +28,10 @@ class MessageKind {
       "no named argument '#{argumentName}' found on method");
   static const METHOD_NOT_FOUND = const MessageKind(
       'no method named #{memberName} in class #{className}');
+  static const OPERATOR_NOT_FOUND = const MessageKind(
+      'no operator #{memberName} in class #{className}');
+  static const PROPERTY_NOT_FOUND = const MessageKind(
+      'no property named #{memberName} in class #{className}');
   static const NOT_CALLABLE = const MessageKind(
       "'#{elementName}' is not callable");
   static const MEMBER_NOT_STATIC = const MessageKind(
@@ -35,6 +39,9 @@ class MessageKind {
   static const NO_INSTANCE_AVAILABLE = const MessageKind(
       '#{name} is only available in instance methods');
 
+  static const THIS_IS_THE_METHOD = const MessageKind(
+      "This is the method declaration.");
+
   static const UNREACHABLE_CODE = const MessageKind(
       'unreachable code');
   static const MISSING_RETURN = const MessageKind(