Use separate random number generator for each randomization pass

src/IceTargetLoweringARM32.cpp

 //===- subzero/src/IceTargetLoweringARM32.cpp - ARM32 lowering ------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 2487 matching lines @@
   // TODO(jvoung): handled folding opportunities. Sign and zero extension
   // can be folded into a load.
   InstAssign *Assign = InstAssign::create(Func, DestLoad, Src0);
   lowerAssign(Assign);
 }
 
 void TargetARM32::doAddressOptLoad() {
   UnimplementedError(Func->getContext()->getFlags());
 }
 
-void TargetARM32::randomlyInsertNop(float Probability) {
-  RandomNumberGeneratorWrapper RNG(Ctx->getRNG());
-  if (RNG.getTrueWithProbability(Probability)) {
+void TargetARM32::randomlyInsertNop(float Probability,
+                                    RandomNumberGenerator &RNG) {
+  RandomNumberGeneratorWrapper RNGW(RNG);
+  if (RNGW.getTrueWithProbability(Probability)) {
     UnimplementedError(Func->getContext()->getFlags());
   }
 }
 
 void TargetARM32::lowerPhi(const InstPhi * /*Inst*/) {
   Func->setError("Phi found in regular instruction list");
 }
 
 void TargetARM32::lowerRet(const InstRet *Inst) {
   Variable *Reg = nullptr;
@@ skipping 516 matching lines @@
       << ".eabi_attribute 68, 1   @ Tag_Virtualization_use\n";
   if (CPUFeatures.hasFeature(TargetARM32Features::HWDivArm)) {
     Str << ".eabi_attribute 44, 2   @ Tag_DIV_use\n";
   }
   // Technically R9 is used for TLS with Sandboxing, and we reserve it.
   // However, for compatibility with current NaCl LLVM, don't claim that.
   Str << ".eabi_attribute 14, 3   @ Tag_ABI_PCS_R9_use: Not used\n";
 }
 
 } // end of namespace Ice