Rollup merge of #97312 - cjgillot:no-path-in-scope, r=compiler-errors

Compute lifetimes in scope at diagnostic time

The set of available lifetimes is currently computed during lifetime resolution on HIR.  It is only used for one diagnostic.

In this PR, HIR lifetime resolution just reports whether elided lifetimes are well-defined at the place of use.  The diagnostic code is responsible for building a list of lifetime names if elision is not allowed.

This will allow to remove lifetime resolution on HIR eventually.

compiler/rustc_hir/src/hir.rs

@@ -3302,6 +3302,7 @@ pub enum Node<'hir> {
     Stmt(&'hir Stmt<'hir>),
     PathSegment(&'hir PathSegment<'hir>),
     Ty(&'hir Ty<'hir>),
+    TypeBinding(&'hir TypeBinding<'hir>),
     TraitRef(&'hir TraitRef<'hir>),
     Binding(&'hir Pat<'hir>),
     Pat(&'hir Pat<'hir>),
@@ -3347,6 +3348,7 @@ impl<'hir> Node<'hir> {
             | Node::PathSegment(PathSegment { ident, .. }) => Some(*ident),
             Node::Lifetime(lt) => Some(lt.name.ident()),
             Node::GenericParam(p) => Some(p.name.ident()),
+            Node::TypeBinding(b) => Some(b.ident),
             Node::Param(..)
             | Node::AnonConst(..)
             | Node::Expr(..)