StableMIR: Add associated_items.

[makai410]

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[makai410]

Lack of the ui-test for it. I open this pr for some feedback first.

[makai410]

My question is what data structure should be used for AssocItems (Currently Vec<(Symbol, AssocItem)>)? btw, I think there may be some problem with OpaqueDef, unsure if my version is correct.

[makai410]

Forgot to mention that there may be some issues with the retrieved associated items that the compiler generated after RPITIT desugaring.

For example:

        trait Ciallo {
            fn rpitit(&self) -> impl std::fmt::Debug {
                "RPITIT"
            }
        }

get all associated items of this trait by associated_items():

AssocItems {
    items: [
        (
            "rpitit",
            AssocItem {
                def_id: AssocDef(
                    DefId {
                        id: 17336,
                        name: "Ciallo::rpitit",
                    },
                ),
                name: "rpitit",
                kind: Fn,
                container: Trait,
                trait_item_def_id: Some(
                    AssocDef(
                        DefId {
                            id: 17336,
                            name: "Ciallo::rpitit",
                        },
                    ),
                ),
                fn_has_self_parameter: true,
                opt_rpitit_info: None,
            },
        ),
        (
            "",
            AssocItem {
                def_id: AssocDef(
                    DefId {
                        id: 17338,
                        name: "Ciallo::{synthetic#0}",
                    },
                ),
                name: "",
                kind: Type,
                container: Trait,
                trait_item_def_id: None,
                fn_has_self_parameter: false,
                opt_rpitit_info: Some(
                    Trait {
                        fn_def_id: FnDef(
                            DefId {
                                id: 17336,
                                name: "Ciallo::rpitit",
                            },
                        ),
                        opaque_def_id: OpaqueDef(
                            DefId {
                                id: 17339,
                                name: "Ciallo::rpitit::{opaque#0}",
                            },
                        ),
                    },
                ),
            },
        ),
    ],
}

The problem is the name of the generated associated type is "". I have no knowledge of RPITIT desugaring, unsure if this is an issue and whether we should slap a name to it.

[celinval]

My question is what data structure should be used for AssocItems (Currently Vec<(Symbol, AssocItem)>)?

Can you do Vec<AssocItem> instead? From what I understood, the Symbol is redundant since it duplicates name from AssocItem.

[makai410]

Oh yes, it makes sense.