Add nonboxed closure class fields.

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 669 matching lines @@
       ..isMixinApplication = false
       ..thisType =
           closureData.rawType = new InterfaceType(cls, const/*<DartType>*/ [])
       ..supertype = supertype
       ..interfaces = const <InterfaceType>[];
     var setBuilder =
         new _KernelOrderedTypeSetBuilder((this as KernelToElementMapBase), cls);
     _classData.add(closureData);
     closureData.orderedTypeSet = setBuilder.createOrderedTypeSet(
         closureData.supertype, const Link<InterfaceType>());
+
+    cls.forEachCapturedVariable((Local local, JField field) {
+      field.setClosureMemberIndex = _memberData.length;
+      //_memberData.add(field);

[Emily Fortuna, 2017/07/19 00:10:30]

This line is commented out because executing it causes these elements to get
added to the codegen work queue, which then causes the SSA builder to request
for the corresponding ir Node: 

NoSuchMethodError: Class 'ClosureField' has no instance getter 'node'.
Receiver: Instance of 'ClosureField'
Tried calling: node
#0      Object._noSuchMethod (dart:core-patch/object_patch.dart:42)
#1      Object.noSuchMethod (dart:core-patch/object_patch.dart:46)
#2      KernelToElementMapBase._getMemberNode
(package:compiler/src/kernel/element_map_impl.dart:606:44)
#3      JsKernelToElementMap.getMemberNode
(package:compiler/src/kernel/element_map_impl.dart:1967:12)
#4      KernelSsaBuilder.build
(package:compiler/src/kernel/kernel_backend_strategy.dart:97:21)
#5      SsaBuilderTask.build (package:compiler/src/ssa/ssa.dart:83:21)
#6      SsaFunctionCompiler.compile (package:compiler/src/ssa/ssa.dart:43:29)
#7      JavaScriptBackend.codegen
(package:compiler/src/js_backend/backend.dart:890:43)
#8      KernelCodegenWorkItem.run
(package:compiler/src/kernel/kernel_backend_strategy.dart:77:21)
#9      Compiler.emptyQueue.<anonymous closure>.<anonymous closure>.<anonymous
closure>.<anonymous closure>.<anonymous closure>
(package:compiler/src/compiler.dart:745:70)

What do you suggest, Johnni?
 

[Johnni Winther, 2017/07/19 10:47:12]

The need for the J-equivalent of ResolvedAst came sooner than expected. I'll
create it today.

+    });
     // TODO(efortuna): Does getMetadata get called in ClassData for this object?
   }
 
   ClassEntity _getClass(ir.Class node, [ClassEnv classEnv]) {
     return _classMap.putIfAbsent(node, () {
       KLibrary library = _getLibrary(node.enclosingLibrary);
       if (classEnv == null) {
         classEnv = _libraryEnvs[library.libraryIndex].lookupClass(node.name);
       }
       _classEnvs.add(classEnv);
@@ skipping 1306 matching lines @@
       if (data.constructorBody != null) {
         f(data.constructorBody);
       }
     });
   }
 
   String getDeferredUri(ir.LibraryDependency node) {
     throw new UnimplementedError('JsKernelToElementMap.getDeferredUri');
   }
 }