Auto merge of #95779 - cjgillot:ast-lifetimes-undeclared, r=petrochenkov

Report undeclared lifetimes during late resolution.

First step in #91557

We reuse the rib design of the current resolution framework. Specific `LifetimeRib` and `LifetimeRibKind` types are introduced. The most important variant is `LifetimeRibKind::Generics`, which happens each time we encounter something which may introduce generic lifetime parameters. It can be an item or a `for<...>` binder. The `LifetimeBinderKind` specifies how this rib behaves with respect to in-band lifetimes.

r? `@petrochenkov`

Author: bors

tests/ui/unused_unit.stderr

@@ -1,8 +1,8 @@
 error: unneeded unit return type
-  --> $DIR/unused_unit.rs:19:28
+  --> $DIR/unused_unit.rs:19:58
    |
 LL |     pub fn get_unit<F: Fn() -> (), G>(&self, f: F, _g: G) -> ()
-   |                            ^^^^^^ help: remove the `-> ()`
+   |                                                          ^^^^^^ help: remove the `-> ()`
    |
 note: the lint level is defined here
   --> $DIR/unused_unit.rs:12:9
@@ -11,16 +11,16 @@ LL | #![deny(clippy::unused_unit)]
    |         ^^^^^^^^^^^^^^^^^^^
 
 error: unneeded unit return type
-  --> $DIR/unused_unit.rs:20:18
+  --> $DIR/unused_unit.rs:19:28
    |
-LL |     where G: Fn() -> () {
-   |                  ^^^^^^ help: remove the `-> ()`
+LL |     pub fn get_unit<F: Fn() -> (), G>(&self, f: F, _g: G) -> ()
+   |                            ^^^^^^ help: remove the `-> ()`
 
 error: unneeded unit return type
-  --> $DIR/unused_unit.rs:19:58
+  --> $DIR/unused_unit.rs:20:18
    |
-LL |     pub fn get_unit<F: Fn() -> (), G>(&self, f: F, _g: G) -> ()
-   |                                                          ^^^^^^ help: remove the `-> ()`
+LL |     where G: Fn() -> () {
+   |                  ^^^^^^ help: remove the `-> ()`
 
 error: unneeded unit return type
   --> $DIR/unused_unit.rs:21:26