Nonsensical extra diagnostics for E0425 in static methods

[nagisa]

The following code (playground):

struct A {
    banana: u8,
}

impl A {
    fn new(peach: u8) -> A {
        A {
            banana: banana // note: banana not in scope here
        }
    }
}

produces the following error:

error[E0425]: cannot find value `banana` in this scope
 --> src/lib.rs:8:21
  |
8 |             banana: banana
  |                     ^^^^^^
  |                     |
  |                     `self` value is a keyword only available in methods with `self` parameter
  |                     help: try: `self.banana`

First, help is wrong, because this is a static method and self is not available in scope. Second it is not clear why a line above help is talking about self at all.

[petrochenkov]

The original logic was to

1. recommend self.banana, that's a common mistake
2. then recommend adding self assuming it's forgotten, that's also a common mistake, which is especially likely if you are referring to something that is named exactly like a field.

Unfortunately, the messages were reworded and repositioned by later changes.