Add associations for more null-aware cases

pkg/compiler/lib/src/kernel/kernel_visitor.dart

 // Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE.md file.
 
 import 'package:kernel/ast.dart' as ir;
 import 'package:kernel/frontend/accessors.dart'
     show
         Accessor,
         IndexAccessor,
         NullAwarePropertyAccessor,
@@ skipping 1495 matching lines @@
   }
 
   Accessor buildNullAwarePropertyAccessor(Node receiver, Name name) {
     return new NullAwarePropertyAccessor(
         visitForValue(receiver), nameToIrName(name), null, null, null);
   }
 
   @override
   ir.Expression visitIfNotNullDynamicPropertyGet(
       Send node, Node receiver, Name name, _) {
-    return buildNullAwarePropertyAccessor(receiver, name).buildSimpleRead();
+    Accessor accessor = buildNullAwarePropertyAccessor(receiver, name);
+    ir.Expression result = accessor.buildSimpleRead();
+    if (accessor.builtGetter != null) {
+      kernel.nodeToAst[accessor.builtGetter] = node;
+    }
+    return result;
   }
 
   @override
   ir.Let visitIfNotNullDynamicPropertyInvoke(
       Send node, Node receiverNode, NodeList arguments, Selector selector, _) {
     ir.VariableDeclaration receiver =
         makeOrReuseVariable(visitForValue(receiverNode));
     return makeLet(
         receiver,
         new ir.ConditionalExpression(
             buildIsNull(new ir.VariableGet(receiver)),
             new ir.NullLiteral(),
-            buildInvokeSelector(new ir.VariableGet(receiver), selector,
-                buildArguments(arguments)),
+            associateNode(
+                buildInvokeSelector(new ir.VariableGet(receiver), selector,
+                                    buildArguments(arguments)),
+                receiverNode),
             null));
   }
 
   @override
   ir.Expression visitIfNotNullDynamicPropertySet(
       SendSet node, Node receiver, Name name, Node rhs, _) {
     return buildNullAwarePropertyAccessor(receiver, name)
         .buildAssignment(visitForValue(rhs), voidContext: isVoidContext);
   }
 
@@ skipping 1299 matching lines @@
       : this(null, true, node, initializers);
 
   accept(ir.Visitor v) => throw "unsupported";
 
   visitChildren(ir.Visitor v) => throw "unsupported";
 
   String toString() {
     return "IrFunction($kind, $isConstructor, $node, $initializers)";
   }
 }