error[E0658]: or-patterns syntax is experimental
  --> $DIR/feature-gate-or_patterns-leading-let.rs:7:9
   |
LL |     let | A;
   |         ^
   |
   = note: see issue #54883 <https://github.com/rust-lang/rust/issues/54883> for more information
   = help: add `#![feature(or_patterns)]` to the crate attributes to enable

error: aborting due to previous error

For more information about this error, try `rustc --explain E0658`.