warning: use of deprecated attribute `plugin`: compiler plugins are deprecated. See https://github.com/rust-lang/rust/pull/64675
  --> $DIR/llvm-pass-plugin.rs:6:1
   |
LL | #![plugin(llvm_pass_plugin)]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: may be removed in a future compiler version
   |
   = note: `#[warn(deprecated)]` on by default