Use failedAt in more places

pkg/compiler/lib/src/kernel/element_map.dart

Index: pkg/compiler/lib/src/kernel/element_map.dart
diff --git a/pkg/compiler/lib/src/kernel/element_map.dart b/pkg/compiler/lib/src/kernel/element_map.dart
index 49ba84766bf1fbb4db0287c576c675dadd9afcbf..eb5ace6bc14a36ca6feafbc97f36451a3235a8ad 100644
--- a/pkg/compiler/lib/src/kernel/element_map.dart
+++ b/pkg/compiler/lib/src/kernel/element_map.dart
@@ -505,8 +505,8 @@ abstract class KernelToElementMapMixin implements KernelToElementMap {
     }
     FunctionEntity function = elementEnvironment.lookupClassMember(
         commonElements.objectClass, Identifiers.noSuchMethod_);
-    assert(invariant(cls, function != null,
-        message: "No super noSuchMethod found for class $cls."));
+    assert(function != null,
+        failedAt(cls, "No super noSuchMethod found for class $cls."));
     return function;
   }
 }