Add ScopeInfo class for variable information that doesn't actually involve closures.

pkg/compiler/lib/src/kernel/closure.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 file.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../closure.dart';
 import '../common/tasks.dart';
 import '../elements/entities.dart';
 import '../world.dart';
@@ skipping 26 matching lines @@
   visitTryFinally(ir.TryFinally node) {
     bool oldInTry = _inTry;
     _inTry = true;
     node.visitChildren(this);
     _inTry = oldInTry;
   }
 
   @override
   visitVariableGet(ir.VariableGet node) {
     if (_inTry) {
-      info.registerUsedInTryOrSync(_localsMap.getLocal(node.variable));
+      info.variablesUsedInTryOrSync.add(_localsMap.getLocal(node.variable));
     }
   }
 
   @override
   visitVariableSet(ir.VariableSet node) {
     if (_inTry) {
-      info.registerUsedInTryOrSync(_localsMap.getLocal(node.variable));
+      info.variablesUsedInTryOrSync.add(_localsMap.getLocal(node.variable));
     }
     node.visitChildren(this);
   }
 }
 
 /// Closure conversion code using our new Entity model. Closure conversion is
 /// necessary because the semantics of closures are slightly different in Dart
 /// than JavaScript. Closure conversion is separated out into two phases:
 /// generation of a new (temporary) representation to store where variables need
 /// to be hoisted/captured up at another level to re-write the closure, and then
@@ skipping 33 matching lines @@
   }
 
   /// TODO(johnniwinther,efortuna): Implement this.
   @override
   LoopClosureRepresentationInfo getClosureRepresentationInfoForLoop(
       ir.Node loopNode) {
     return const LoopClosureRepresentationInfo();
   }
 
   @override
+  ScopeInfo getScopeInfo(Entity entity) {
+    // TODO(efortuna): Specialize this function from the one below.
+    return getClosureRepresentationInfo(entity);
+  }
+
+  @override
   ClosureRepresentationInfo getClosureRepresentationInfo(Entity entity) {
     return _infoMap.putIfAbsent(entity, () {
       if (entity is MemberEntity) {
         ir.Member node = _elementMap.getMemberNode(entity);
         ThisLocal thisLocal;
         if (entity.isInstanceMember) {
           thisLocal = new ThisLocal(entity);
         }
         KernelClosureDataBuilder builder = new KernelClosureDataBuilder(
             _globalLocalsMap.getLocalsMap(entity), thisLocal);
         node.accept(builder);
         return builder.info;
       }
 
       /// TODO(johnniwinther,efortuna): Implement this.
       return const ClosureRepresentationInfo();
     });
   }
 }
 
 // TODO(johnniwinther): Add unittest for the computed
 // [ClosureRepresentationInfo].
 class KernelClosureRepresentationInfo extends ClosureRepresentationInfo {
   final ThisLocal thisLocal;
-  final Set<Local> _localsUsedInTryOrSync = new Set<Local>();
+  final Set<Local> variablesUsedInTryOrSync = new Set<Local>();
 
   KernelClosureRepresentationInfo(this.thisLocal);
 
-  void registerUsedInTryOrSync(Local local) {
-    _localsUsedInTryOrSync.add(local);
-  }
-
-  bool variableIsUsedInTryOrSync(Local variable) =>
-      _localsUsedInTryOrSync.contains(variable);
-
   String toString() {
     StringBuffer sb = new StringBuffer();
     sb.write('this=$thisLocal,');
-    sb.write('localsUsedInTryOrSync={${_localsUsedInTryOrSync.join(', ')}}');
+    sb.write(
+        'variablesUsedInTryOrSync={${variablesUsedInTryOrSync.join(', ')}}');
     return sb.toString();
   }
 }