Add a test for macros default! and union!

Author: calixteman

corpus/macros.txt

@@ -28,6 +28,8 @@ a!(b + c + +);
 a!('a'..='z');
 a!('\u{0}'..='\u{2}');
 a!('lifetime)
+default!(a);
+union!(a);
 
 ----
 
@@ -50,6 +52,12 @@ a!('lifetime)
   (macro_invocation
     (identifier)
     (token_tree (char_literal) (char_literal)))
+  (macro_invocation
+    (identifier)
+    (token_tree (identifier)))
+  (macro_invocation
+    (identifier)
+    (token_tree (identifier)))
   (macro_invocation
     (identifier)
     (token_tree (identifier))))