Remove hir::MacroDef::attrs.

compiler/rustc_hir/src/hir.rs

@@ -768,7 +768,6 @@ impl Crate<'_> {
 pub struct MacroDef<'hir> {
     pub ident: Ident,
     pub vis: Visibility<'hir>,
-    pub attrs: &'hir [Attribute],
     pub def_id: LocalDefId,
     pub span: Span,
     pub ast: ast::MacroDef,