Use failedAt in more places

pkg/compiler/lib/src/js_backend/patch_resolver.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 dart2js.js_backend.patch_resolver;
 
 import '../common.dart';
 import '../common/resolution.dart' show Resolution;
 import '../common/tasks.dart' show CompilerTask;
 import '../compiler.dart' show Compiler;
@@ skipping 36 matching lines @@
 
     assert(originParameters.length == patchParameters.length);
     for (int index = 0; index < originParameters.length; index++) {
       ParameterElementX originParameter = originParameters[index];
       ParameterElementX patchParameter = patchParameters[index];
       // TODO(johnniwinther): Remove the conditional patching when we never
       // resolve the same method twice.
       if (!originParameter.isPatched) {
         originParameter.applyPatch(patchParameter);
       } else {
-        assert(invariant(origin, originParameter.patch == patchParameter,
-            message: "Inconsistent repatch of $originParameter."));
+        assert(originParameter.patch == patchParameter,
+            failedAt(origin, "Inconsistent repatch of $originParameter."));
       }
       ResolutionDartType originParameterType =
           originParameter.computeType(resolution);
       ResolutionDartType patchParameterType =
           patchParameter.computeType(resolution);
       if (originParameterType != patchParameterType) {
         reporter.reportError(
             reporter.createMessage(
                 originParameter, MessageKind.PATCH_PARAMETER_TYPE_MISMATCH, {
               'methodName': origin.name,
@@ skipping 107 matching lines @@
           'originParameterCount': originSignature.optionalParameterCount,
           'patchParameterCount': patchSignature.optionalParameterCount
         });
       });
     } else {
       checkMatchingPatchParameters(origin, originSignature.optionalParameters,
           patchSignature.optionalParameters);
     }
   }
 }