rustc_ast: Do not panic by default when visiting macro calls

compiler/rustc_expand/src/config.rs

@@ -547,11 +547,6 @@ impl<'a> MutVisitor for StripUnconfigured<'a> {
         noop_flat_map_assoc_item(configure!(self, item), self)
     }
 
-    fn visit_mac(&mut self, _mac: &mut ast::MacCall) {
-        // Don't configure interpolated AST (cf. issue #34171).
-        // Interpolated AST will get configured once the surrounding tokens are parsed.
-    }
-
     fn visit_pat(&mut self, pat: &mut P<ast::Pat>) {
         self.configure_pat(pat);
         noop_visit_pat(pat, self)