Compute source spans for IR nodes and J/K-elements

pkg/compiler/lib/src/js_model/js_strategy.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.js_model.strategy;
 
 import '../closure.dart' show ClosureConversionTask;
+import '../common.dart';
 import '../common/tasks.dart';
 import '../common_elements.dart';
 import '../compiler.dart';
 import '../elements/elements.dart' show TypedefElement;
 import '../elements/entities.dart';
 import '../enqueue.dart';
 import '../io/source_information.dart';
 import '../js_emitter/sorter.dart';
 import '../js/js_source_mapping.dart';
 import '../js_backend/backend.dart';
@@ skipping 183 matching lines @@
       NativeBasicData nativeBasicData,
       ClosedWorld closedWorld,
       SelectorConstraintsStrategy selectorConstraintsStrategy) {
     return new KernelCodegenWorldBuilder(
         elementMap,
         closedWorld.elementEnvironment,
         nativeBasicData,
         closedWorld,
         selectorConstraintsStrategy);
   }
+
+  @override
+  SourceSpan spanFromSpannable(Spannable spannable, Entity currentElement) {
+    return _elementMap.getSourceSpan(spannable, currentElement);
+  }
 }
 
 class JsRuntimeTypesNeed implements RuntimeTypesNeed {
   final JsToFrontendMap _map;
   final RuntimeTypesNeed _rtiNeed;
 
   JsRuntimeTypesNeed(this._map, this._rtiNeed);
 
   @override
   bool classNeedsRti(ClassEntity cls) {
@@ skipping 13 matching lines @@
   @override
   bool methodNeedsRti(FunctionEntity function) {
     return _rtiNeed.methodNeedsRti(_map.toFrontendMember(function));
   }
 
   @override
   bool classNeedsRtiField(ClassEntity cls) {
     return _rtiNeed.classNeedsRtiField(_map.toFrontendClass(cls));
   }
 }