Rollup merge of #96948 - ludfo774:macro-trailing-comma-test, r=joshtriplett

Add test of matches macro for trailing commas

Almost all macros are tested for trailing commas.
The macro matches! was however not tested.
This PR adds that test case.
Related to #46238

src/test/ui/macros/macro-comma-support-rpass.rs

@@ -192,6 +192,12 @@ fn line() {
     let _ = line!();
 }
 
+#[test]
+fn matches() {
+    let _ = matches!(1, x if x > 0);
+    let _ = matches!(1, x if x > 0,);
+}
+
 #[test]
 fn module_path() {
     let _ = module_path!();