kernel->ssa: implement for-in loops

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 417 matching lines @@
     }
   }
 
   ir.Statement buildForInCommon(
       ForIn node, ir.VariableDeclaration variable, ir.Statement body,
       {bool isAsync}) {
     ir.Expression iterable = visitForValue(node.expression);
     JumpTarget jumpTarget = elements.getTargetDefinition(node);
     body = buildContinueTarget(body, node, jumpTarget);
     return buildBreakTarget(
-        new ir.ForInStatement(variable, iterable, body, isAsync: isAsync),
+        associateNode(
+            new ir.ForInStatement(variable, iterable, body, isAsync: isAsync),
+            node),
         node,
         jumpTarget);
   }
 
   /// Builds a for-in statement for this case:
   ///
   ///     for (constOrVarOrType loopVariable in expression) body
   ir.Statement buildForInWithDeclaration(
       ForIn node, VariableDefinitions declaration,
       {bool isAsync}) {
@@ skipping 2325 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)";
   }
 }