error: expected identifier, found keyword `let`
  --> $DIR/removed-syntax-field-let.rs:4:5
   |
LL |     let foo: (),
   |     ^^^ expected identifier, found keyword
help: you can escape reserved keywords to use them as identifiers
   |
LL |     r#let foo: (),
   |     ^^^^^

error: expected `:`, found `foo`
  --> $DIR/removed-syntax-field-let.rs:4:9
   |
LL |     let foo: (),
   |         ^^^ expected `:`

error: aborting due to 2 previous errors