Insert NoDelim groups around nonterminals when lowering macro_rules

src/test/ui/proc-macro/nested-macro-rules.rs

@@ -0,0 +1,20 @@
+// run-pass
+// aux-build:nested-macro-rules.rs
+// aux-build:test-macros.rs
+// compile-flags: -Z span-debug
+// edition:2018
+
+extern crate nested_macro_rules;
+extern crate test_macros;
+
+use test_macros::print_bang;
+
+use nested_macro_rules::FirstStruct;
+struct SecondStruct;
+
+fn main() {
+    nested_macro_rules::inner_macro!(print_bang);
+
+    nested_macro_rules::outer_macro!(SecondStruct);
+    inner_macro!(print_bang);
+}