message: genx: run GenXLayoutBlocksPass in optlevel > 0
diff: @@ -623,6 +623,7 @@ void Optimize(llvm::Module *module, int optLevel) {
  optPM.add(CreateInstructionSimplifyPass());
  #ifdef ISPC_GENX_ENABLED
  if (g->target->getISA() == Target::GENX) {
  + optPM.add(llvm::createGenXLayoutBlocksPass());
  optPM.add(llvm::createCMSimdCFLoweringPass());
  optPM.add(llvm::createGenXPacketizePass());
  optPM.add(llvm::createPromoteMemoryToRegisterPass());
  