dart2js: type analysis: yield escapes its argument

pkg/compiler/lib/src/inferrer/inferrer_engine.dart

 // Copyright (c) 2017, 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 file.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
 import '../constants/expressions.dart';
@@ skipping 901 matching lines @@
    */
   TypeInformation registerAwait(ast.Node node, TypeInformation argument) {
     AwaitTypeInformation info =
         new AwaitTypeInformation(types.currentMember, node);
     info.addAssignment(argument);
     types.allocatedTypes.add(info);
     return info;
   }
 
   /**
+   * Registers a call to yield with an expression of type [argumentType] as
+   * argument.
+   */
+  TypeInformation registerYield(ast.Node node, TypeInformation argument) {
+    YieldTypeInformation info =
+        new YieldTypeInformation(types.currentMember, node);
+    info.addAssignment(argument);
+    types.allocatedTypes.add(info);
+    return info;
+  }
+
+  /**
    * Registers that [caller] calls [closure] with [arguments].
    *
    * [sideEffects] will be updated to incorporate the potential
    * callees' side effects.
    *
    * [inLoop] tells whether the call happens in a loop.
    */
   TypeInformation registerCalledClosure(
       ast.Node node,
       Selector selector,
@@ skipping 129 matching lines @@
   /**
    * Records that the captured variable [local] is read.
    */
   void recordCapturedLocalRead(Local local) {}
 
   /**
    * Records that the variable [local] is being updated.
    */
   void recordLocalUpdate(Local local, TypeInformation type) {}
 }