[SubZero] Fix f64 to/from i64 moves

src/IceTargetLoweringX86BaseImpl.h

 //===- subzero/src/IceTargetLoweringX86BaseImpl.h - x86 lowering -*- C++ -*-==//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 3986 matching lines @@
     Variable *T = makeReg(Ty);
     _movp(T, Slot);
     _movp(Instr->getDest(), T);
   }
 }
 
 template <typename TraitsType>
 void TargetX86Base<TraitsType>::lowerIntrinsicCall(
     const InstIntrinsicCall *Instr) {
   switch (Intrinsics::IntrinsicID ID = Instr->getIntrinsicInfo().ID) {
-  default:
-    llvm::report_fatal_error("Unexpected intrinsic");
-    return;
   case Intrinsics::AtomicCmpxchg: {
     if (!Intrinsics::isMemoryOrderValid(
             ID, getConstantMemoryOrder(Instr->getArg(3)),
             getConstantMemoryOrder(Instr->getArg(4)))) {
       Func->setError("Unexpected memory ordering for AtomicCmpxchg");
       return;
     }
     Variable *DestPrev = Instr->getDest();
     Operand *PtrToMem = legalize(Instr->getArg(0));
     Operand *Expected = legalize(Instr->getArg(1));
@@ skipping 2064 matching lines @@
       _movp(T, Src0RM);
       _punpckl(T, Src0RM);
       _movp(Dest, T);
       return;
     }
 
     if (Instr->indexesAre(0, 8, 1, 9, 2, 10, 3, 11)) {
       auto *T = makeReg(DestTy);
       auto *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
       auto *Src1RM = legalize(Src1, Legal_Reg | Legal_Mem);
+      (void)Src1RM;
       _movp(T, Src0RM);
       _punpckl(T, Src0RM);
       _movp(Dest, T);
       return;
     }
 
     if (Instr->indexesAre(4, 4, 5, 5, 6, 6, 7, 7)) {
       auto *T = makeReg(DestTy);
       auto *Src0RM = legalize(Src0, Legal_Reg | Legal_Mem);
       _movp(T, Src0RM);
@@ skipping 2147 matching lines @@
         emitGlobal(*Var, SectionSuffix);
       }
     }
   } break;
   }
 }
 } // end of namespace X86NAMESPACE
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGX86BASEIMPL_H