Subzero: Randomize register assignment.

src/IceRNG.h

 //===- subzero/src/IceRNG.h - Random number generator -----------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares a random number generator.
@@ skipping 24 matching lines @@
 
 // This class adds additional random number generator utilities. The
 // reason for the wrapper class is that we want to keep the
 // RandomNumberGenerator interface identical to LLVM's.
 class RandomNumberGeneratorWrapper {
   RandomNumberGeneratorWrapper(const RandomNumberGeneratorWrapper &) = delete;
   RandomNumberGeneratorWrapper &
   operator=(const RandomNumberGeneratorWrapper &) = delete;
 
 public:
-  uint64_t next(uint64_t Max) { return RNG.next(Max); }
+  uint64_t operator()(uint64_t Max) { return RNG.next(Max); }
   bool getTrueWithProbability(float Probability);
   RandomNumberGeneratorWrapper(RandomNumberGenerator &RNG) : RNG(RNG) {}
 
 private:
   RandomNumberGenerator &RNG;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICERNG_H