E0425 needs to be updated to new format

[sophiajt]

From: src/test/compile-fail/E0033.rs

Error E0425 needs a span_label, updating it from:

error[E0425]: unresolved name `SomeTrait`
  --> src/test/compile-fail/E0033.rs:16:33
   |
16 |     let trait_obj: &SomeTrait = SomeTrait; //~ ERROR E0425
   |                                 ^^^^^^^^^
   |
   = help: trait `SomeTrait` cannot be used as an expression

To:

error[E0425]: unresolved name `SomeTrait`
  --> src/test/compile-fail/E0033.rs:16:33
   |
16 |     let trait_obj: &SomeTrait = SomeTrait; //~ ERROR E0425
   |                                 ^^^^^^^^^ unresolved name
   |
   = help: trait `SomeTrait` cannot be used as an expression

Note, this assumes we can know this information when we're making the label.

Edit: I've updated the default label above

[sophiajt]

A note to who is doing this one, it seems E0425 is used for a few styles of errors. For example:

error[E0425]: unresolved name `varaible`. Did you mean `variable`?
 --> quicktest.rs:3:11
  |
3 |   let x = varaible;
  |           ^^^^^^^^

The "Did you mean variable?" part should be a label, if it exists. Which turns the above into:

error[E0425]: unresolved name `varaible`.
 --> quicktest.rs:3:11
  |
3 |   let x = varaible;
  |           ^^^^^^^^ did you mean `variable`?

[sophiajt]

One more note. I've updated the default label. Basically, we'll have a default label if there is no "did you mean..." part, otherwise if there is a "did you mean..." we'll use that as the label.

[sophiajt]

For @prabodhtiwari (who I think volunteered for this one). I made a couple changes. If you have any questions, just tag me and ask.

[bstrie]

Freeing this one up as part of the final push for #35233.