message: Clean up conditional compilation
diff: @@ -12,7 +12,7 @@ fn tmp() -> PathBuf {
  std::env::var("MIRI_TEMP").map(PathBuf::from).unwrap_or_else(|_| std::env::temp_dir())
  }
  -#[cfg(not(target_os = "macos"))]
  +#[cfg(target_os = "linux")]
  fn test_posix_fadvise() {
  use std::convert::TryInto;
  use std::fs::{remove_file, File};
  @@ -144,7 +144,7 @@ fn test_rwlock_libc_static_initializer() {
  }
  fn main() {
  - #[cfg(not(target_os = "macos"))]
  + #[cfg(target_os = "linux")]
  test_posix_fadvise();
  test_mutex_libc_init_recursive();
  