Only omit trailing comma if block doesn't come from macro expansion

src/test/ui/issue-94866.rs

@@ -0,0 +1,14 @@
+macro_rules! m {
+    () => {
+        {}
+    };
+}
+
+enum Enum { A, B }
+
+fn main() {
+    match Enum::A {
+    //~^ ERROR non-exhaustive patterns
+    Enum::A => m!()
+    }
+}

src/test/ui/issue-94866.stderr

@@ -0,0 +1,21 @@
+error[E0004]: non-exhaustive patterns: `B` not covered
+  --> $DIR/issue-94866.rs:10:11
+   |
+LL |     match Enum::A {
+   |           ^^^^^^^ pattern `B` not covered
+   |
+note: `Enum` defined here
+  --> $DIR/issue-94866.rs:7:16
+   |
+LL | enum Enum { A, B }
+   |      ----      ^ not covered
+   = note: the matched value is of type `Enum`
+help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
+   |
+LL ~     Enum::A => m!(),
+LL +     B => todo!()
+   |
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0004`.

src/test/ui/pattern/usefulness/tuple-struct-nonexhaustive.stderr

@@ -12,7 +12,7 @@ LL | struct Foo(isize, isize);
    = note: the matched value is of type `Foo`
 help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
    |
-LL ~         Foo(2, b) => println!("{}", b)
+LL ~         Foo(2, b) => println!("{}", b),
 LL +         Foo(_, _) => todo!()
    |