Feature request: Generate type definition from struct or enum literal

It would be really nice for quick prototyping if there was an assist that could generate a struct or enum definition given a corresponding literal with an undefined type name at the front.

Record struct:

let foo = Foo$0 { field: "hello".to_owned() };

// generate type definition
struct Foo {
    field: String,
}

Tuple struct:

let foo = Foo$0("world");

// generate type definition
struct Foo<'a>(&'a str);

Enum:

let bar = Foo$0::Bar;
let baz = Foo::Baz;

// generate type definition
enum Foo {
    Bar,
    Baz,
}

(and equivalent for enums with tuple or record fields)

The issue names no files, tests, or entry points. Start by locating rust-analyzer's assist handling for undefined types and use the record, tuple-struct, and enum examples as acceptance cases. Done means generating struct or enum definitions, including tuple or record fields and required lifetimes, from the literals shown.