dart2js: type analysis: yield escapes its argument

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

 // Copyright (c) 2013, 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.
 
 library simple_types_inferrer;
 
 import '../closure.dart' show ClosureClassMap;
 import '../common.dart';
 import '../common/names.dart' show Identifiers, Selectors;
 import '../compiler.dart' show Compiler;
@@ skipping 2271 matching lines @@
       }
     }
     return null;
   }
 
   TypeInformation visitAwait(ast.Await node) {
     TypeInformation futureType = node.expression.accept(this);
     return inferrer.registerAwait(node, futureType);
   }
 
+  TypeInformation visitYield(ast.Yield node) {
+    TypeInformation operandType = node.expression.accept(this);
+    return inferrer.registerYield(node, operandType);
+  }
+
   TypeInformation handleTypeLiteralInvoke(ast.NodeList arguments) {
     // This is reached when users forget to put a `new` in front of a type
     // literal. The emitter will generate an actual call (even though it is
     // likely invalid), and for that it needs to have the arguments processed
     // as well.
     analyzeArguments(arguments.nodes);
     return types.dynamicType;
   }
 
   /// Handle constructor invocation of [constructor].
@@ skipping 640 matching lines @@
     Selector moveNextSelector = Selectors.moveNext;
     TypeMask moveNextMask = inTreeData.typeOfIteratorMoveNext(node);
 
     TypeInformation iteratorType = handleDynamicSend(node, iteratorSelector,
         iteratorMask, expressionType, new ArgumentsTypes.empty());
 
     return handleForInLoop(node, iteratorType, currentSelector, currentMask,
         moveNextSelector, moveNextMask);
   }
 }