Faster invocation of custom comparator function.

test/mjsunit/fuzz-natives.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 142 matching lines @@
   "ResolvePossiblyDirectEval": true,
   "Log": true,
   "DeclareGlobals": true,
 
   "PromoteScheduledException": true,
   "DeleteHandleScopeExtensions": true,
 
   // That can only be invoked on Array.prototype.
   "FinishArrayPrototypeSetup": true,
 
+  // Performance critical function which cannot afford type checks.
+  "_CallFunction": true,
+
   // LiveEdit feature is under development currently and has fragile input.
   "LiveEditFindSharedFunctionInfosForScript": true,
   "LiveEditGatherCompileInfo": true,
   "LiveEditReplaceScript": true,
   "LiveEditReplaceFunctionCode": true,
   "LiveEditRelinkFunctionToScript": true,
   "LiveEditPatchFunctionPositions": true,
   "LiveEditCheckStackActivations": true
 };
 
@@ skipping 10 matching lines @@
     if (name in knownProblems || name in currentlyUncallable)
       continue;
     print(name);
     var argc = nativeInfo[1];
     testArgumentCount(name, argc);
     testArgumentTypes(name, argc);
   }
 }
 
 testNatives();