error: field expressions cannot have generic arguments
  --> $DIR/bad-name.rs:2:12
   |
LL |   let x.y::<isize>.z foo;
   |            ^^^^^^^

error: expected a pattern, found an expression
  --> $DIR/bad-name.rs:2:7
   |
LL |   let x.y::<isize>.z foo;
   |       ^^^^^^^^^^^^^^ arbitrary expressions are not allowed in patterns

error: expected one of `(`, `.`, `::`, `:`, `;`, `=`, `?`, `|`, or an operator, found `foo`
  --> $DIR/bad-name.rs:2:22
   |
LL |   let x.y::<isize>.z foo;
   |                      ^^^ expected one of 9 possible tokens

error: aborting due to 3 previous errors