Record in HIR whether lifetime elision was succesful.

compiler/rustc_middle/src/ty/mod.rs

@@ -207,6 +207,8 @@ pub struct ResolverAstLowering {
     /// A small map keeping true kinds of built-in macros that appear to be fn-like on
     /// the surface (`macro` items in libcore), but are actually attributes or derives.
     pub builtin_macro_kinds: FxHashMap<LocalDefId, MacroKind>,
+    /// List functions and methods for which lifetime elision was successful.
+    pub lifetime_elision_allowed: FxHashSet<ast::NodeId>,
 }
 
 #[derive(Clone, Copy, Debug)]