Fix the locals lookup of variables and partial implementation of boxing of variables.

pkg/compiler/lib/src/kernel/element_map.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 '../closure.dart';
 import '../common.dart';
 import '../constants/values.dart';
 import '../common_elements.dart';
@@ skipping 226 matching lines @@
   ir.Node get node;
 
   /// The canonical location of [member]. This is used for sorting the members
   /// in the emitted code.
   SourceSpan get location;
 }
 
 enum ClassKind {
   regular,
   closure,
+  // TODO(efortuna, johnniwinther): Container is not a class, but is
+  // masquerading as one currently for consistency with the old element model.
+  container,
 }
 
 /// A member directly defined by its [ir.Member] node.
 class RegularMemberDefinition implements MemberDefinition {
   final MemberEntity member;
   final ir.Member node;
 
   RegularMemberDefinition(this.member, this.node);
 
   SourceSpan get location => computeSourceSpanFromTreeNode(node);
@@ skipping 119 matching lines @@
   MemberEntity get currentMember;
 
   // TODO(johnniwinther): Make these return the [KernelToLocalsMap] to use from
   // now on.
   /// Call to notify that [member] is currently being inlined.
   void enterInlinedMember(covariant MemberEntity member);
 
   /// Call to notify that [member] is no longer being inlined.
   void leaveInlinedMember(covariant MemberEntity member);
 
-  /// Returns the [Local] for [node].
-  Local getLocalVariable(ir.VariableDeclaration node);
+  /// Returns the [Local] for [node]. If [isClosureCallMethod] is true, this
+  /// gives the locals map permission to also look one scope higher within the
+  /// class for the corresponding local. This can happen in the case of free
+  /// variables involved with a closure class.
+  Local getLocalVariable(ir.VariableDeclaration node,
+      {bool isClosureCallMethod = false});
 
   /// Returns the [Local] corresponding to the [node]. The node must be either
   /// a [ir.FunctionDeclaration] or [ir.FunctionExpression].
   Local getLocalFunction(ir.TreeNode node);
 
   /// Returns the [JumpTarget] for the break statement [node].
   JumpTarget getJumpTargetForBreak(ir.BreakStatement node);
 
   /// Returns `true` if [node] should generate a `continue` to its [JumpTarget].
   bool generateContinueForBreak(ir.BreakStatement node);
@@ skipping 51 matching lines @@
       uri = Uri.parse(node.location.file);
       break;
     }
     node = node.parent;
   }
   if (uri != null) {
     return new SourceSpan(uri, offset, offset + 1);
   }
   return null;
 }