error: expected pattern, found `let`
  --> $DIR/unnecessary-let.rs:4:9
   |
LL |     for let _x of [1, 2, 3] {}
   |         ^^^
   |
help: remove the unnecessary `let` keyword
   |
LL -     for let _x of [1, 2, 3] {}
LL +     for _x of [1, 2, 3] {}
   |

error: missing `in` in `for` loop
  --> $DIR/unnecessary-let.rs:4:16
   |
LL |     for let _x of [1, 2, 3] {}
   |                ^^
   |
help: try using `in` here instead
   |
LL |     for let _x in [1, 2, 3] {}
   |                ~~

error: expected pattern, found `let`
  --> $DIR/unnecessary-let.rs:9:9
   |
LL |         let 1 => {}
   |         ^^^
   |
help: remove the unnecessary `let` keyword
   |
LL -         let 1 => {}
LL +         1 => {}
   |

error: aborting due to 3 previous errors