Add test that reproduces misalignment of help under note

Author: dtolnay

src/tests/ghost-note-help.rs

@@ -0,0 +1,41 @@
+test_normalize! {"
+error[E0004]: non-exhaustive patterns: `MyPhantom::__Phantom(_)` not covered
+  --> src/main.rs:9:11
+   |
+ 9 |     match phantom {
+   |           ^^^^^^^ pattern `MyPhantom::__Phantom(_)` not covered
+   |
+note: `MyPhantom<u8>` defined here
+  --> src/main.rs:4:8
+   |
+ 3 | #[phantom]
+   | ---------- not covered
+ 4 | struct MyPhantom<T: ?Sized>;
+   |        ^^^^^^^^^
+   = note: the matched value is of type `MyPhantom<u8>`
+help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
+   |
+10 ~         MyPhantom => {},
+11 +         MyPhantom::__Phantom(_) => todo!()
+   |
+" "
+error[E0004]: non-exhaustive patterns: `MyPhantom::__Phantom(_)` not covered
+ --> src/main.rs:9:11
+  |
+9 |     match phantom {
+  |           ^^^^^^^ pattern `MyPhantom::__Phantom(_)` not covered
+  |
+note: `MyPhantom<u8>` defined here
+ --> src/main.rs:4:8
+  |
+3 | #[phantom]
+  | ---------- not covered
+4 | struct MyPhantom<T: ?Sized>;
+  |        ^^^^^^^^^
+  = note: the matched value is of type `MyPhantom<u8>`
+help: ensure that all possible cases are being handled by adding a match arm with a wildcard pattern or an explicit pattern as shown
+  |
+10 ~         MyPhantom => {},
+11 +         MyPhantom::__Phantom(_) => todo!()
+   |
+"}