E0002 needs to be updated to new format

[sophiajt]

From: src/test/compile-fail/E0002.rs

Errror E0002 needs a label and help moved to a simple help, updating it from:

error[E0002]: non-exhaustive patterns: type std::option::Option<i32> is non-empty
  --> src/test/compile-fail/E0002.rs:14:5
   |
14 |     match x { } //~ ERROR E0002
   |     ^^^^^^^^^^^
   |
help: Please ensure that all possible cases are being handled; possibly adding wildcards or more match arms.
  --> src/test/compile-fail/E0002.rs:14:5
   |
14 |     match x { } //~ ERROR E0002
   |     ^^^^^^^^^^^

To:

error[E0002]: non-exhaustive patterns: type std::option::Option<i32> is non-empty
  --> src/test/compile-fail/E0002.rs:14:5
   |
14 |     match x { } //~ ERROR E0002
   |     ^^^^^^^^^^^ not all cases are handled
   |
   = note: this may be fixed by possibly adding wildcards or more match arms.

[srdja]

I can work on this.

edit: I see it has already been assigned. I guess I'll have to find something else to work on. :)

[arielb1]

This error is basically a hack and should be merged into E0004.

[bstrie]

I've opened #36724 to address @arielb1's comment. In the meantime, I'm leaving it up to @jonathandturner as to whether this issue should be addressed as normal or if we should close this outright. In the meantime, I'm operating under the assumption that this will remain open, and am offering it to anyone as a part of #35233 .

[jfirebaugh]

#36909 has been merged and E0002 is now unused (modulo #37058), so this can be closed.

[sophiajt]

Let's go ahead and close those. We'll likely end up doing a sweep over the errors once the last errors are update and we move many of the compile-fail tests over to ui tests.