Fix unecessary break due to comment in polymorphic variants (#2606)

The previous formatting was:

    | (* Other inline element markup. *)
      `Simple_reference of
      string

CHANGES.md

@@ -96,7 +96,7 @@ profile. This started with version 0.26.0.
 - \* Consistent break after string constant argument (#2453, @Julow)
 - \* Fix cinaps comment formatting to not change multiline string contents (#2463, @tdelvecchio-jsc)
 - \* Fix the indentation of tuples in attributes and extensions (#2488, @Julow)
-- \* Fix unwanted alignment after comment (#2507, #2589, @Julow)
+- \* Fix weird indentation and line breaks after comments (#2507, #2589, #2606, @Julow)
 - \* Fix unwanted alignment in if-then-else (#2511, @Julow)
 - Fix missing parentheses around constraint expressions with attributes (#2513, @alanechang)
 - Fix formatting of type vars in GADT constructors (#2518, @Julow)

lib/Fmt_ast.ml

@@ -1064,7 +1064,7 @@ and fmt_row_field c ctx {prf_desc; prf_attributes; prf_loc} =
     | Rinherit typ -> fmt_core_type c (sub_typ ~ctx typ)
   in
   hvbox 0
-    ( hvbox (Params.Indent.variant_type_arg c.conf) (Cmts.fmt c prf_loc row)
+    ( Cmts.fmt c prf_loc (hvbox (Params.Indent.variant_type_arg c.conf) row)
     $ fmt_attributes_and_docstrings c prf_attributes )
 
 and fmt_pattern_attributes c xpat k =

test/passing/tests/variants.ml

@@ -14,3 +14,9 @@ let _ = (* xx *) `(* yy *) A (* zz *)
 let _ = (* xx *) `B (* zz *)
 
 let _ = `(* yy *) C (* zz *)
+
+type t =
+  [ `Fooooo
+  | (* Other inline element markup. *)
+    `Simple_reference of string
+  | `Fooooo ]