Improve some comments

ocaml/testsuite/tests/typing-layouts-products/basics.ml

@@ -83,7 +83,7 @@ Error: This type #(int * int) should be an instance of type
        But the layout of #(int * int) must be a sublayout of value & bits64
          because of the definition of t3 at line 1, characters 0-34.
 |}]
-(* CR layouts 7.1: The above error should identify the component of the product
+(* CR layouts v7.1: The above error should identify the component of the product
    that is problematic. *)
 
 (* some mutually recusive types *)
@@ -122,7 +122,7 @@ Error: This type #(int * int64) should be an instance of type
          because of the annotation on 'a in the declaration of the type
                                       t6_wrong.
 |}]
-(* CR layouts 7.1: The above error should identify the component of the product
+(* CR layouts v7.1: The above error should identify the component of the product
    that is problematic. *)
 
 (* Just like t6/t7, but with the annotation on the other (the order doesn't
@@ -600,7 +600,7 @@ Error: This value escapes its region.
 (*********************)
 (* Test 9: externals *)
 
-(* CR layouts 7.1: Unboxed products should be allowed for some primitives, like
+(* CR layouts v7.1: Unboxed products should be allowed for some primitives, like
    %identity *)
 
 type t_product : value & value
@@ -685,7 +685,7 @@ Error: Unboxed product layouts are not yet supported as arguments to
        The layout of this argument is value & value.
 |}]
 
-(* CR layouts 7.1: Unboxed products should be allowed for some primitives, like
+(* CR layouts v7.1: Unboxed products should be allowed for some primitives, like
    %identity *)
 
 (***********************************)
@@ -778,12 +778,13 @@ type t3 = #(int * bool) array
 type t4 = #(string * #(float# * bool option)) array
 |}]
 
-(* CR layouts 7.1: This example demonstrates a bug in type inference that we
+(* CR layouts v7.1: This example demonstrates a bug in type inference that we
    should fix.  The issue is the way typing of tuple expressions works - we
-   create type variables at generic level (I'm confused about why not current
-   level) and then constrain them by the expected type.  This will fail if it
-   requires to refine the kind, because we don't allow refining kinds at generic
-   level. Further thinking required. *)
+   create type variables at generic level and then constrain them by the
+   expected type.  This will fail if it requires to refine the kind, because we
+   don't allow refining kinds at generic level.  We need to remove the
+   restriction that kinds of things at generic level can't be modified, but that
+   is orthogonal to unboxed tuples so we leave in this sad bug for now. *)
 let _ = [| #(1,2) |]
 [%%expect{|
 Line 1, characters 11-17:

ocaml/typing/jkind.ml

@@ -1831,7 +1831,7 @@ let is_nary_product n t =
   in
   if Misc.Le_result.is_le (Jkind_desc.sub t.jkind bound)
   then
-    (* CR layouts 7.1: The histories here are wrong (we are giving each
+    (* CR layouts v7.1: The histories here are wrong (we are giving each
        component the history of the whole product).  They don't show up in
        errors, so it's fine for now, but we'll probably need to fix this as
        part of improving errors around products. A couple options: re-work the

ocaml/typing/typedecl.ml

@@ -2947,7 +2947,7 @@ let unexpected_layout_any_check prim env cty ty =
       [@layout_poly].
 
       An exception is raised if any of these checks fails. *)
-(* CR layouts 7.1: additionally, we do not allow externals to have unboxed
+(* CR layouts v7.1: additionally, we do not allow externals to have unboxed
    product args/returns. Right now this restriction is in place for all
    externals, but we should be able to relax it for some primitives that are
    implemented by the compiler, like %identity. Enforcement for [@layout_poly]

ocaml/typing/typeopt.ml

@@ -714,7 +714,7 @@ let[@inline always] rec layout_of_const_sort_generic ~value_kind ~error
                             Language_extension.(is_enabled Small_numbers) ->
     Lambda.Punboxed_float Pfloat32
   | Product consts when Language_extension.(is_at_least Layouts Beta) ->
-    (* CR layouts 7.1: assess whether it is important for performance to support
+    (* CR layouts v7.1: assess whether it is important for performance to support
        deep value_kinds here *)
     Lambda.Punboxed_product
       (List.map (layout_of_const_sort_generic ~value_kind:(lazy Pgenval) ~error)