Use failedAt in more places (constants, universe)

pkg/compiler/lib/src/universe/codegen_world_builder.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.
 
 part of world_builder;
 
 /// World builder specific to codegen.
 ///
 /// This adds additional access to liveness of selectors and elements.
 abstract class CodegenWorldBuilder implements WorldBuilder {
@@ skipping 496 matching lines @@
       MethodElement function, void f(DartType type, String name)) {
     FunctionSignature parameters = function.functionSignature;
     parameters.forEachParameter((ParameterElement parameter) {
       f(parameter.type, parameter.name);
     });
   }
 
   @override
   void _processInstantiatedClassMember(
       ClassEntity cls, MemberElement member, MemberUsedCallback memberUsed) {
-    assert(invariant(member, member.isDeclaration));
+    assert(member.isDeclaration, failedAt(member));
     if (member.isMalformed) return;
     super._processInstantiatedClassMember(cls, member, memberUsed);
   }
 
   @override
   _MemberUsage _getMemberUsage(
       MemberElement member, MemberUsedCallback memberUsed) {
-    assert(invariant(member, member.isDeclaration));
+    assert(member.isDeclaration, failedAt(member));
     return super._getMemberUsage(member, memberUsed);
   }
 
   void registerStaticUse(StaticUse staticUse, MemberUsedCallback memberUsed) {
     Element element = staticUse.element;
-    assert(invariant(element, element.isDeclaration,
-        message: "Element ${element} is not the declaration."));
+    assert(element.isDeclaration,
+        failedAt(element, "Element ${element} is not the declaration."));
     super.registerStaticUse(staticUse, memberUsed);
   }
 
   /// Register the constant [use] with this world builder. Returns `true` if
   /// the constant use was new to the world.
   @override
   bool registerConstantUse(ConstantUse use) {
     if (use.kind == ConstantUseKind.DIRECT) {
       _constants.addCompileTimeConstantForEmission(use.value);
     }
@@ skipping 30 matching lines @@
     throw new UnimplementedError('KernelCodegenWorldBuilder.forEachParameter');
   }
 
   @override
   void forEachInstanceField(
       ClassEntity cls, void f(ClassEntity declarer, FieldEntity field)) {
     throw new UnimplementedError(
         'KernelCodegenWorldBuilder.forEachInstanceField');
   }
 }