Introduce new-style attribute parsers for several attributes

note: compiler compiles but librustdoc and clippy don't

compiler/rustc_privacy/src/lib.rs

@@ -22,6 +22,7 @@ use errors::{
 };
 use rustc_ast::MacroDef;
 use rustc_ast::visit::{VisitorResult, try_visit};
+use rustc_attr_parsing::AttributeKind;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::intern::Interned;
 use rustc_errors::{MultiSpan, listify};
@@ -493,7 +494,11 @@ impl<'tcx> EmbargoVisitor<'tcx> {
         // Non-opaque macros cannot make other items more accessible than they already are.
         let hir_id = self.tcx.local_def_id_to_hir_id(local_def_id);
         let attrs = self.tcx.hir().attrs(hir_id);
-        if attr::find_transparency(attrs, md.macro_rules).0 != Transparency::Opaque {
+
+        if attr::find_attr!(attrs, AttributeKind::MacroTransparency(x) => *x)
+            .unwrap_or(Transparency::fallback(md.macro_rules))
+            != Transparency::Opaque
+        {
             return;
         }