Switch to a bitflags `MacroKinds` to support macros with more than one kind

Review everything that uses `MacroKind`, and switch anything that could
refer to more than one kind to use `MacroKinds`.

Add a new `SyntaxExtensionKind::MacroRules` for `macro_rules!` macros,
using the concrete `MacroRulesMacroExpander` type, and have it track
which kinds it can handle. Eliminate the separate optional `attr_ext`,
now that a `SyntaxExtension` can handle multiple macro kinds.

This also avoids the need to downcast when calling methods on
`MacroRulesMacroExpander`, such as `get_unused_rule`.

Integrate macro kind checking into name resolution's
`sub_namespace_match`, so that we only find a macro if it's the right
type, and eliminate the special-case hack for attributes.

1 files changed, 2 insertions, 2 deletions

diff --git a/compiler/rustc_lint/src/non_local_def.rs b/compiler/rustc_lint/src/non_local_def.rs
index b877f909fc0..e6507fe6149 100644
--- a/compiler/rustc_lint/src/non_local_def.rs
+++ b/compiler/rustc_lint/src/non_local_def.rs
@@ -5,7 +5,7 @@ use rustc_hir::{Body, HirId, Item, ItemKind, Node, Path, TyKind};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::{declare_lint, impl_lint_pass};
 use rustc_span::def_id::{DefId, LOCAL_CRATE};
-use rustc_span::{ExpnKind, MacroKind, Span, kw, sym};
+use rustc_span::{ExpnKind, Span, kw, sym};
 
 use crate::lints::{NonLocalDefinitionsCargoUpdateNote, NonLocalDefinitionsDiag};
 use crate::{LateContext, LateLintPass, LintContext, fluent_generated as fluent};
@@ -240,7 +240,7 @@ impl<'tcx> LateLintPass<'tcx> for NonLocalDefinitions {
                     },
                 )
             }
-            ItemKind::Macro(_, _macro, MacroKind::Bang)
+            ItemKind::Macro(_, _macro, _kinds)
                 if cx.tcx.has_attr(item.owner_id.def_id, sym::macro_export) =>
             {
                 cx.emit_span_lint(