error: expected one of `.`, `?`, `]`, or an operator, found `,`
  --> $DIR/do-not-suggest-semicolon-between-macro-without-exclamation-mark-and-array.rs:2:19
   |
LL |     let _x = vec[1, 2, 3];
   |                   ^ expected one of `.`, `?`, `]`, or an operator

error: aborting due to 1 previous error