Attach tokens to ast::Stmt

We currently only attach tokens when parsing a `:stmt` matcher for a
`macro_rules!` macro. Proc-macro attributes on statements are still
unstable, and need additional work.

compiler/rustc_interface/src/util.rs

@@ -710,6 +710,7 @@ impl<'a> MutVisitor for ReplaceBodyWithLoop<'a, '_> {
                 id: resolver.next_node_id(),
                 kind: ast::StmtKind::Expr(expr),
                 span: rustc_span::DUMMY_SP,
+                tokens: None,
             }
         }
 
@@ -726,6 +727,7 @@ impl<'a> MutVisitor for ReplaceBodyWithLoop<'a, '_> {
             id: self.resolver.next_node_id(),
             span: rustc_span::DUMMY_SP,
             kind: ast::StmtKind::Expr(loop_expr),
+            tokens: None,
         };
 
         if self.within_static_or_const {