Recover from invalid `struct` item syntax
Parse unsupported "default field const values":
```rust
struct S {
field: Type = const_val,
}
```
Recover from small `:` typo and provide suggestion:
```rust
struct S {
field; Type,
field2= Type,
}
```
|
||
|---|---|---|
| .. | ||
| lexer | ||
| parser | ||
| lib.rs | ||
| validate_attr.rs | ||