Added for-loop variable tracking and regular closures/initializers captured variable tracking.

pkg/compiler/lib/src/kernel/element_map_impl.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.
 
 library dart2js.kernel.element_map;
 
 import 'package:kernel/ast.dart' as ir;
 import 'package:kernel/clone.dart';
 import 'package:kernel/type_algebra.dart';
 
@@ skipping 756 matching lines @@
     _KClassEnv env = _classEnvs[cls.classIndex];
     _ensureSupertypes(cls, env);
     return env.interfaces;
   }
 
   ir.Library getKernelLibrary(KLibrary entity) =>
       _libraryEnvs[entity.libraryIndex].library;
 
   ir.Class getKernelClass(KClass entity) => _classEnvs[entity.classIndex].cls;
 
+  ir.Member getKernelMember(KMember entity) =>
+      _memberList[entity.memberIndex].node;
+
   bool hasConstantFieldInitializer(covariant KField field) {
     _FieldData data = _memberList[field.memberIndex];
     return getFieldConstantValue(data.node) != null;
   }
 
   ConstantValue getConstantFieldInitializer(covariant KField field) {
     _FieldData data = _memberList[field.memberIndex];
     ConstantValue value = getFieldConstantValue(data.node);
     assert(value != null,
         failedAt(field, "Field $field doesn't have a constant initial value."));
@@ skipping 1036 matching lines @@
     return _elementMap.getSpannable(_map.toFrontendMember(member), node);
   }
 
   @override
   LibraryEntity getLibrary(ir.Library node) {
     return _map.toBackendLibrary(_elementMap.getLibrary(node));
   }
 
   @override
   Local getLocalFunction(ir.TreeNode node) {
-    throw new UnsupportedError("JsKernelToElementMap.getLocalFunction");
+    // TODO(efortuna, johnniwinther): This function should not be called once
+    // the K + J element situation has been properly sorted out. Ultimately this
+    // should throw.
+    return _elementMap.getLocalFunction(node);
   }
 
   @override
   ClassEntity getClass(ir.Class node) {
     return _map.toBackendClass(_elementMap.getClass(node));
   }
 
   @override
   FieldEntity getField(ir.Field node) {
     return _map.toBackendMember(_elementMap.getField(node));
@@ skipping 90 matching lines @@
     throw new UnsupportedError(
         "JsKernelToElementMap.getConstantFieldInitializer");
   }
 
   @override
   bool hasConstantFieldInitializer(FieldEntity field) {
     throw new UnsupportedError(
         "JsKernelToElementMap.hasConstantFieldInitializer");
   }
 }