Marks this field as the captured caller location, surfaced via
`Diagnostic::oopsie_location`. The field's type must be
`&'static Location<'static>` (the standard `std::panic::Location`); it is
auto-captured (and excluded from the selector). Marking a field is only needed
when its type isn't recognized automatically.
Forms: `location`, `location = true`, `location = false`.
### Example
```
use std::panic::Location;
#[oopsie::oopsie]
#[oopsie(module(false))]
pub enum AppError {
#[oopsie("boom")]
Boom {
#[oopsie(location)]
at: &'static Location<'static>,
},
}
let err = Boom.build();
assert_eq!(err.to_string(), "boom");
```