Subzero: Fix a warning (promoted to an error) under NOASSERT=1 build.

src/IceInstX8632.cpp

 //===- subzero/src/IceInstX8632.cpp - X86-32 instruction implementation ---===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the InstX8632 and OperandX8632 classes,
@@ skipping 462 matching lines @@
       Asm->jmp(RegX8632::getEncodedGPR(Var->getRegNum()));
     } else {
       // The jmp instruction with a memory operand should be possible
       // to encode, but it isn't a valid sandboxed instruction, and
       // there shouldn't be a register allocation issue to jump
       // through a scratch register, so we don't really need to bother
       // implementing it.
       llvm::report_fatal_error("Assembler can't jmp to memory operand");
     }
   } else if (const auto Mem = llvm::dyn_cast<OperandX8632Mem>(Target)) {
+    (void)Mem;
     assert(Mem->getSegmentRegister() == OperandX8632Mem::DefaultSegment);
     llvm::report_fatal_error("Assembler can't jmp to memory operand");
   } else if (const auto CR = llvm::dyn_cast<ConstantRelocatable>(Target)) {
     assert(CR->getOffset() == 0 && "We only support jumping to a function");
     Asm->jmp(CR);
   } else if (const auto Imm = llvm::dyn_cast<ConstantInteger32>(Target)) {
     // NaCl trampoline calls refer to an address within the sandbox directly.
     // This is usually only needed for non-IRT builds and otherwise not
     // very portable or stable. For this, we would use the 0xE8 opcode
     // (relative version of call) and there should be a PC32 reloc too.
@@ skipping 2452 matching lines @@
   }
   Str << "(";
   if (Func)
     Var->dump(Func);
   else
     Var->dump(Str);
   Str << ")";
 }
 
 } // end of namespace Ice