Subzero: Randomize register assignment.

src/IceTargetLoweringX8632.h

Index: src/IceTargetLoweringX8632.h
diff --git a/src/IceTargetLoweringX8632.h b/src/IceTargetLoweringX8632.h
index ebe6ba91752814786142633131a3c28bab265392..d1e0cc7cc486ac2d83a72f3333306025bed3f55d 100644
--- a/src/IceTargetLoweringX8632.h
+++ b/src/IceTargetLoweringX8632.h
@@ -181,6 +181,10 @@ protected:
   OperandX8632Mem *getMemoryOperandForStackSlot(Type Ty, Variable *Slot,
                                                 uint32_t Offset = 0);
 
+  void
+  makeRandomRegisterPermutation(llvm::SmallVectorImpl<int32_t> &Permutation,
+                                const llvm::SmallBitVector &ExcludeRegisters);
+
   // The following are helpers that insert lowered x86 instructions
   // with minimal syntactic overhead, so that the lowering code can
   // look as close to assembly as practical.