Auto merge of #121587 - ShoyuVanilla:fix-issue-121267, r=TaKO8Ki

Fix bad span for explicit lifetime suggestions

Fixes #121267

Current explicit lifetime suggestions are not showing correct spans for some lifetimes - e.g. elided lifetime generic parameters;

This should be done correctly regarding elided lifetime kind like the following code

43fdd4916d/compiler/rustc_resolve/src/late/diagnostics.rs (L3015-L3044)

compiler/rustc_hir/src/def.rs

@@ -810,6 +810,8 @@ pub enum LifetimeRes {
         param: NodeId,
         /// Id of the introducing place. See `Param`.
         binder: NodeId,
+        /// Kind of elided lifetime
+        kind: hir::MissingLifetimeKind,
     },
     /// This variant is used for anonymous lifetimes that we did not resolve during
     /// late resolution. Those lifetimes will be inferred by typechecking.

compiler/rustc_hir/src/hir.rs

@@ -456,6 +456,18 @@ impl GenericBound<'_> {
 
 pub type GenericBounds<'hir> = &'hir [GenericBound<'hir>];
 
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, HashStable_Generic, Debug)]
+pub enum MissingLifetimeKind {
+    /// An explicit `'_`.
+    Underscore,
+    /// An elided lifetime `&' ty`.
+    Ampersand,
+    /// An elided lifetime in brackets with written brackets.
+    Comma,
+    /// An elided lifetime with elided brackets.
+    Brackets,
+}
+
 #[derive(Copy, Clone, Debug, HashStable_Generic)]
 pub enum LifetimeParamKind {
     // Indicates that the lifetime definition was explicitly declared (e.g., in
@@ -464,7 +476,7 @@ pub enum LifetimeParamKind {
 
     // Indication that the lifetime was elided (e.g., in both cases in
     // `fn foo(x: &u8) -> &'_ u8 { x }`).
-    Elided,
+    Elided(MissingLifetimeKind),
 
     // Indication that the lifetime name was somehow in error.
     Error,
@@ -512,7 +524,7 @@ impl<'hir> GenericParam<'hir> {
     ///
     /// See `lifetime_to_generic_param` in `rustc_ast_lowering` for more information.
     pub fn is_elided_lifetime(&self) -> bool {
-        matches!(self.kind, GenericParamKind::Lifetime { kind: LifetimeParamKind::Elided })
+        matches!(self.kind, GenericParamKind::Lifetime { kind: LifetimeParamKind::Elided(_) })
     }
 }