Implementation of null-aware operators.

pkg/compiler/lib/src/resolved_visitor.dart

Index: pkg/compiler/lib/src/resolved_visitor.dart
diff --git a/pkg/compiler/lib/src/resolved_visitor.dart b/pkg/compiler/lib/src/resolved_visitor.dart
index 2459c0534ef5ebfe708c27c3c736ff755c67a374..51af7807d15722b52a9695087351f038ead88b84 100644
--- a/pkg/compiler/lib/src/resolved_visitor.dart
+++ b/pkg/compiler/lib/src/resolved_visitor.dart
@@ -575,6 +575,15 @@ class ResolvedSemanticDispatcher<R> extends Object
   }
 
   @override
+  R visitIfNull(
+      Send node,
+      Node left,
+      Node right,
+      ResolvedKindVisitor<R> visitor) {
+    return visitor.visitOperatorSend(node);
+  }
+
+  @override
   R visitLogicalAnd(
       Send node,
       Node left,
@@ -629,6 +638,16 @@ class ResolvedSemanticDispatcher<R> extends Object
   }
 
   @override
+  R visitIfNotNullDynamicPropertyInvoke(
+      Send node,
+      Node receiver,
+      NodeList arguments,
+      Selector selector,
+      ResolvedKindVisitor<R> visitor) {
+    return visitor.visitDynamicSend(node);
+  }
+
+  @override
   R visitThisPropertyInvoke(
       Send node,
       NodeList arguments,