message: enable llvm assembly support for aarch64
diff: #![feature(alloc_error_handler)]
  #![feature(vec_into_raw_parts)]
  #![feature(drain_filter)]
  +#![feature(llvm_asm)]
  +#![feature(global_asm)]
  #![no_std]
  #![cfg_attr(target_os = "hermit", feature(custom_test_frameworks))]
  #![cfg_attr(target_os = "hermit", cfg_attr(test, test_runner(crate::test_runner)))]
  