message: [XLA:CPU] Put function into an llvm::Module
  LLVM APIs don't like free-floating functions. Fixes an error with clang's
  fsanitize=null.
diff: @@ -37,10 +37,10 @@ StatusOr<unsigned> GetTargetVectorRegisterByteSize(std::string triple) {
  }
  llvm::LLVMContext context;
  - std::unique_ptr<llvm::Function> function =
  - absl::WrapUnique(llvm::Function::Create(
  + llvm::Module module("test", context);
  + llvm::Function* function = llvm::Function::Create(
  llvm::FunctionType::get(llvm::Type::getVoidTy(context), {}),
  - llvm::GlobalValue::ExternalLinkage, "test"));
  + llvm::GlobalValue::ExternalLinkage, "test", &module);
  std::unique_ptr<llvm::TargetMachine> target_machine =
  absl::WrapUnique(target->createTargetMachine(
  