Revert "Non-format-changing kernel offset changes"

pkg/kernel/lib/transformations/async.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.
 
 library kernel.transformations.async;
 
 import '../kernel.dart';
 import 'continuation.dart';
 
 /// A transformer that introduces temporary variables for all subexpressions
@@ skipping 391 matching lines @@
     ++nameIndex;
     seenAwait = seenAwait || thenAwait || otherwiseAwait;
     return new VariableGet(result);
   }
 
   // Others.
   TreeNode visitAwaitExpression(AwaitExpression expr) {
     final R = continuationRewriter;
     var shouldName = seenAwait;
     var result = new VariableGet(asyncResult);
-
     // The statements are in reverse order, so name the result first if
     // necessary and then add the two other statements in reverse.
     if (shouldName) result = name(result);
-    statements.add(R.createContinuationPoint()..fileOffset = expr.fileOffset);
+    statements.add(R.createContinuationPoint());
     Arguments arguments = new Arguments(<Expression>[
       expr.operand,
       new VariableGet(R.thenContinuationVariable),
       new VariableGet(R.catchErrorContinuationVariable)
     ]);
     statements.add(new ExpressionStatement(
-        new StaticInvocation(R.helper.awaitHelper, arguments)
-          ..fileOffset = expr.fileOffset));
+        new StaticInvocation(R.helper.awaitHelper, arguments)));
 
     seenAwait = false;
     var index = nameIndex;
     arguments.positional[0] = expr.operand.accept(this)..parent = arguments;
 
     if (shouldName) nameIndex = index + 1;
     seenAwait = true;
     return result;
   }
 
@@ skipping 46 matching lines @@
       });
     }
   }
 
   visitFunctionNode(FunctionNode node) {
     var nestedRewriter =
         new RecursiveContinuationRewriter(continuationRewriter.helper);
     return node.accept(nestedRewriter);
   }
 }