warning: use of deprecated attribute `plugin`: compiler plugins are deprecated. See https://github.com/rust-lang/rust/issues/29597
  --> $DIR/llvm-pass-plugin.rs:6:1
   |
LL | #![plugin(llvm_pass_plugin)]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove this attribute
   |
   = note: `#[warn(deprecated)]` on by default