Reapply "Added for-loop variable tracking and regular closures/initializers captured variable track…

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 '../common.dart';
 import '../common/names.dart' show Identifiers;
@@ skipping 1764 matching lines @@
 
   @override
   LibraryEntity _getLibrary(ir.Library node, [LibraryEnv env]) {
     LibraryEntity library = _libraryMap[node];
     assert(library != null, "No library entity for $node");
     return library;
   }
 
   @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 _getLocalFunction(node);
   }
 
   @override
   ClassEntity _getClass(ir.Class node, [ClassEnv env]) {
     ClassEntity cls = _classMap[node];
     assert(cls != null, "No class entity for $node");
     return cls;
   }
 
   // TODO(johnniwinther): Reinsert these when [ElementCreatorMixin] is no longer
@@ skipping 22 matching lines @@
   @override
   ir.Member getMemberNode(MemberEntity member) {
     return _getMemberNode(member);
   }
 
   @override
   ir.Class getClassNode(ClassEntity cls) {
     return _getClassNode(cls);
   }
 }