Put Macros inside of the ResolverArena

Author: LorrensP-2158466

compiler/rustc_resolve/src/lib.rs

@@ -1025,6 +1025,21 @@ impl MacroData {
     }
 }
 
+pub(crate) type Macro<'ra> = Interned<'ra, MacroData>;
+
+// Allows us to use Interned without actually enforcing (via Hash/PartialEq/...) uniqueness of the
+// contained data.
+// FIXME: We may wish to actually have at least debug-level assertions that Interned's guarantees
+// are upheld.
+impl std::hash::Hash for MacroData {
+    fn hash<H>(&self, _: &mut H)
+    where
+        H: std::hash::Hasher,
+    {
+        unreachable!()
+    }
+}
+
 /// The main resolver class.
 ///
 /// This is the visitor that walks the whole crate.
@@ -1241,6 +1256,7 @@ pub struct ResolverArenas<'ra> {
     imports: TypedArena<ImportData<'ra>>,
     name_resolutions: TypedArena<RefCell<NameResolution<'ra>>>,
     ast_paths: TypedArena<ast::Path>,
+    macros: TypedArena<MacroData>,
     dropless: DroplessArena,
 }