error: expected one of `async`, `const`, `crate`, `default`, `extern`, `fn`, `pub`, `type`, or `unsafe`, found `}`
  --> $DIR/issue-20711.rs:5:1
   |
LL |     #[stable(feature = "rust1", since = "1.0.0")]
   |                                                  - expected one of 9 possible tokens here
LL | }
   | ^ unexpected token

error: aborting due to previous error