Add source information to variable declarations in CPS.

pkg/compiler/lib/src/js_backend/codegen/codegen.dart

 // Copyright (c) 2014, 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 code_generator;
 
 import 'glue.dart';
 
 import '../../closure.dart' show
     ClosureClassElement;
@@ skipping 166 matching lines @@
       if (declaredVariables.contains(name)) continue;
       js.VariableInitialization jsVariable = new js.VariableInitialization(
         new js.VariableDeclaration(name),
         null);
       jsVariables.add(jsVariable);
     }
 
     if (jsVariables.length > 0) {
       // Would be nice to avoid inserting at the beginning of list.
       accumulator.insert(0, new js.ExpressionStatement(
-          new js.VariableDeclarationList(jsVariables)));
+          new js.VariableDeclarationList(jsVariables)
+              .withSourceInformation(function.sourceInformation)));
     }
     return new js.Fun(parameters, new js.Block(accumulator));
   }
 
   @override
   js.Expression visitExpression(tree_ir.Expression node) {
     js.Expression result = node.accept(this);
     if (result == null) {
       glue.reportInternalError('$node did not produce code.');
     }
@@ skipping 1045 matching lines @@
   void registerDefaultParameterValues(ExecutableElement element) {
     if (element is! FunctionElement) return;
     FunctionElement function = element;
     if (function.isStatic) return; // Defaults are inlined at call sites.
     function.functionSignature.forEachOptionalParameter((param) {
       ConstantValue constant = glue.getDefaultParameterValue(param);
       registry.registerCompileTimeConstant(constant);
     });
   }
 }