E0063 needs to be updated to new format

[sophiajt]

From: src/test/compile-fail/E0063.rs

Error E0063 needs a span_label, updating it from:

error[E0063]: missing field `y` in initializer of `Foo`
  --> src/test/compile-fail/E0063.rs:17:13
   |
17 |     let x = Foo { x: 0 }; //~ ERROR E0063
   |             ^^^

To:

error[E0063]: missing field `y` in initializer of `Foo`
  --> src/test/compile-fail/E0063.rs:17:13
   |
17 |     let x = Foo { x: 0 }; //~ ERROR E0063
   |             ^^^ missing `y` field

[jaredwy]

@jonathandturner this one can be closed and checked off in the larger issue now that the PR has landed.