Use failedAt in more places

pkg/compiler/lib/src/resolution/signatures.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.resolution.signatures;
 
 import '../common.dart';
 import '../common/resolution.dart';
 import '../elements/resolution_types.dart';
 import '../elements/elements.dart';
@@ skipping 130 matching lines @@
         // Inline function typed parameter, like `void m(int f(String s))`.
         computeInlineFunctionType(link.head);
       } else if (link.head.asSend() != null &&
           link.head.asSend().selector.asFunctionExpression() != null) {
         // Inline function typed initializing formal or
         // parameter with default value, like `C(int this.f(String s))` or
         // `void m([int f(String s) = null])`.
         computeInlineFunctionType(
             link.head.asSend().selector.asFunctionExpression());
       } else {
-        assert(invariant(currentDefinitions,
-            link.head.asIdentifier() != null || link.head.asSend() != null));
+        assert(link.head.asIdentifier() != null || link.head.asSend() != null,
+            failedAt(currentDefinitions));
         if (fieldElement != null) {
           element.typeCache = fieldElement.computeType(resolution);
         } else {
           element.typeCache = const ResolutionDynamicType();
         }
       }
     }
   }
 
   FormalElementX visitIdentifier(Identifier node) {
@@ skipping 195 matching lines @@
         createRealParameters: createRealParameters);
     List<Element> parameters = const <Element>[];
     int requiredParameterCount = 0;
     if (formalParameters == null) {
       if (!element.isGetter) {
         if (element.isMalformed) {
           // If the element is erroneous, an error should already have been
           // reported. In the case of parse errors, it is possible that there
           // are formal parameters, but something else in the method failed to
           // parse. So we suppress the message about missing formals.
-          assert(invariant(element, reporter.hasReportedError));
+          assert(reporter.hasReportedError, failedAt(element));
         } else {
           reporter.reportErrorMessage(element, MessageKind.MISSING_FORMALS);
         }
       }
     } else {
       if (element.isGetter) {
         if (!identical(
             formalParameters.endToken.next.stringValue,
             // TODO(ahe): Remove the check for native keyword.
             'native')) {
@@ skipping 126 matching lines @@
 /// variables of the function signature itself when its signature is analyzed.
 class FunctionSignatureBuildingScope extends TypeVariablesScope {
   @override
   final List<ResolutionDartType> typeVariables;
 
   FunctionSignatureBuildingScope(Scope parent, this.typeVariables)
       : super(parent);
 
   String toString() => 'FunctionSignatureBuildingScope($typeVariables)';
 }