Update test

src/test/ui/macros/trace_faulty_macros.rs

@@ -13,7 +13,7 @@ macro_rules! pat_macro {
         pat_macro!(A{a:a, b:0, c:_, ..});
     };
     ($a:pat) => {
-        $a
+        $a //~ ERROR expected expression
     };
 }
 

src/test/ui/macros/trace_faulty_macros.stderr

@@ -49,5 +49,16 @@ LL |     my_recursive_macro!();
    = note: expanding `my_recursive_macro! {  }`
    = note: to `my_recursive_macro ! () ;`
 
-error: aborting due to 2 previous errors
+error: expected expression, found `A { a: a, b: 0, c: _, .. }`
+  --> $DIR/trace_faulty_macros.rs:16:9
+   |
+LL |         $a
+   |         ^^ expected expression
+...
+LL |     let a = pat_macro!();
+   |             ------------ in this macro invocation
+   |
+   = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
+
+error: aborting due to 3 previous errors