dart2js cps: Track existence of try statements in resolution instead of traversing AST/IR nodes to …

pkg/compiler/lib/src/resolution/tree_elements.dart

 // Copyright (c) 2015, 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.resolution.tree_elements;
 
 import '../constants/expressions.dart';
 import '../dart_types.dart';
 import '../diagnostics/invariant.dart' show
     invariant;
@@ skipping 104 matching lines @@
   JumpTarget getTargetDefinition(Node node);
 
   /// Returns the jump target of the [node].
   JumpTarget getTargetOf(GotoStatement node);
 
   /// Returns the label defined by [node].
   LabelDefinition getLabelDefinition(Label node);
 
   /// Returns the label that [node] targets.
   LabelDefinition getTargetLabel(GotoStatement node);
+
+  /// `true` if the [analyzedElement]'s source code contains a [TryStatement].
+  bool get containsTryStatement;
 }
 
 class TreeElementMapping extends TreeElements {
   final AnalyzableElement analyzedElement;
   Map<Spannable, Selector> _selectors;
   Map<Spannable, TypeMask> _typeMasks;
   Map<Node, DartType> _types;
   Setlet<Node> _superUses;
   Setlet<Element> _otherDependencies;
   Map<Node, ConstantExpression> _constants;
   Map<VariableElement, List<Node>> _potentiallyMutated;
   Map<Node, Map<VariableElement, List<Node>>> _potentiallyMutatedIn;
   Map<VariableElement, List<Node>> _potentiallyMutatedInClosure;
   Map<Node, Map<VariableElement, List<Node>>> _accessedByClosureIn;
   Setlet<Element> _elements;
   Setlet<Send> _asserts;
   Maplet<Send, SendStructure> _sendStructureMap;
   Setlet<DartType> _requiredTypes;
+  bool containsTryStatement = false;
 
   /// Map from nodes to the targets they define.
   Map<Node, JumpTarget> _definedTargets;
 
   /// Map from goto statements to their targets.
   Map<GotoStatement, JumpTarget> _usedTargets;
 
   /// Map from labels to their label definition.
   Map<Label, LabelDefinition> _definedLabels;
 
@@ skipping 393 matching lines @@
   }
 
   void setCurrentTypeMask(ForIn node, TypeMask mask) {
     _setTypeMask(node.inToken, mask);
   }
 
   TypeMask getCurrentTypeMask(ForIn node) {
     return _getTypeMask(node.inToken);
   }
 }