Merge #6818

6818: Add Lifetimes to the HIR r=matklad a=Veykril

This doesn't handle resolve yet as I don't know yet how that will be used. I'll get to that once I start moving the lifetime reference PR to the hir.

This also adds a new `hir` name type for lifetimes and labels, `hir::LifetimeName`.

Co-authored-by: Lukas Wirth <lukastw97@gmail.com>

crates/hir_def/src/lib.rs

@@ -224,6 +224,13 @@ pub struct TypeParamId {
 
 pub type LocalTypeParamId = Idx<generics::TypeParamData>;
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub struct LifetimeParamId {
+    pub parent: GenericDefId,
+    pub local_id: LocalLifetimeParamId,
+}
+pub type LocalLifetimeParamId = Idx<generics::LifetimeParamData>;
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum ContainerId {
     ModuleId(ModuleId),