rustc-ap-rustc_error_codes 638.0.0

Automatically published version of the package `rustc_error_codes` in the rust-lang/rust repository from commit 30ca215b4e38b32aa7abdd635c5e2d56f5724494 The publishing script for this crate lives at: https://github.com/alexcrichton/rustc-auto-publish
Documentation
#### Note: this error code is no longer emitted by the compiler.

The `pub` keyword was used inside a public enum.

Erroneous code example:

```compile_fail
pub enum Foo {
    pub Bar, // error: unnecessary `pub` visibility
}
```

Since the enum is already public, adding `pub` on one its elements is
unnecessary. Example:

```compile_fail
enum Foo {
    pub Bar, // not ok!
}
```

This is the correct syntax:

```
pub enum Foo {
    Bar, // ok!
}
```