E0165 needs to be updated to new format

[sophiajt]

From: src/test/compile-fail/E0165.rs

Error E0165 needs a span_label, updating it from:

error[E0165]: irrefutable while-let pattern
  --> src/test/compile-fail/E0165.rs:15:15
   |
15 |     while let Irrefutable(x) = irr { //~ ERROR E0165
   |               ^^^^^^^^^^^^^^

To:

error[E0165]: irrefutable while-let pattern
  --> src/test/compile-fail/E0165.rs:15:15
   |
15 |     while let Irrefutable(x) = irr { //~ ERROR E0165
   |               ^^^^^^^^^^^^^^ irrefutable pattern