Revert "Rollup merge of #82296 - spastorino:pubrules, r=nikomatsakis"

This reverts commit e2561c58a4, reversing
changes made to 2982ba50fc.

compiler/rustc_ast_passes/src/feature_gate.rs

@@ -691,7 +691,6 @@ pub fn check_crate(krate: &ast::Crate, sess: &Session) {
         // involved, so we only emit errors where there are no other parsing errors.
         gate_all!(destructuring_assignment, "destructuring assignments are unstable");
     }
-    gate_all!(pub_macro_rules, "`pub` on `macro_rules` items is unstable");
 
     // All uses of `gate_all!` below this point were added in #65742,
     // and subsequently disabled (with the non-early gating readded).