normalize tests by removing all trailing whitespace which some OCaml …

…versions add

https://ci.ocaml.org/ocaml/opam-repository/pr/15897?test=3%20Compilers
Test failed for OCaml 4.02 because of no trailing whitespace after the declared variants:
-  | A of int
-  | B of int
+  | A of int
+  | B of int
And failed for 4.03-4.05 with extra trailing whitespace (after _ pattern or last case?):
-  function | (A x, _) when x <> 0 -> 1 | (_, A x) when x <> 0 -> 1 | _ -> 2
+  function | (A x, _) when x <> 0 -> 1 | (_, A x) when x <> 0 -> 1 | _ -> 2
 let g x =
   match x with
   | (A x, _) when x <> 0 -> 1
   | (_, A x) when x <> 0 -> 1
   | (B x, _) when x <> 0 -> 1
-  | _ -> 2
+  | _ -> 2

dune

@@ -24,12 +24,12 @@
   (action (run ./%{pp} --impl %{input} -o %{targets}))
 )
 
-; The PPX for OCaml 4.02-4.05 prints no whitespace in tuples, so we add them. See https://github.com/ocaml/opam-repository/pull/15897
+; The PPX for OCaml 4.02-4.05 prints no whitespace in tuples, so we add them. They also add trailing whitespace in some places, which we remove everywhere. See https://github.com/ocaml/opam-repository/pull/15897
 (rule
   (targets test.actual.norm.ml)
   (deps (:input test.actual.ml))
-  ; sed -E 's/,([^ ])/, \1/' test.actual.ml > test.actual.norm.ml
-  (action (with-stdout-to test.actual.norm.ml (run sed -E "s/,([^ ])/, \\1/g" %{input})))
+  ; sed -E 's/,([^ ])/, \1/g; s/ *$//' test.actual.ml > test.actual.norm.ml
+  (action (with-stdout-to test.actual.norm.ml (run sed -E "s/,([^ ])/, \\1/g; s/ *$//" %{input})))
 )
 
 (rule

test.expected.ml

@@ -1,6 +1,6 @@
 type t =
-  | A of int 
-  | B of int 
+  | A of int
+  | B of int
 let f =
   function | (A x, _) when x <> 0 -> 1 | (_, A x) when x <> 0 -> 1 | _ -> 2
 let g x =