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
Attempted to pass an invalid type of variable into a variadic function.

Erroneous code example:

```compile_fail,E0617
extern {
    fn printf(c: *const i8, ...);
}

unsafe {
    printf(::std::ptr::null(), 0f32);
    // error: cannot pass an `f32` to variadic function, cast to `c_double`
}
```

Certain Rust types must be cast before passing them to a variadic function,
because of arcane ABI rules dictated by the C standard. To fix the error,
cast the value to the type specified by the error message (which you may need
to import from `std::os::raw`).