refactor: Install.Entry.to_dyn (#7536)

Signed-off-by: Rudi Grinberg <me@rgrinberg.com>

src/dune_rules/install.ml

@@ -397,6 +397,21 @@ module Entry = struct
     ; dst = Dst.of_install_file ~section ~src_basename:(Path.basename src) dst
     ; kind = `File
     }
+
+  let dyn_of_kind =
+    let open Dyn in
+    function
+    | `File -> variant "File" []
+    | `Directory -> variant "Directory" []
+
+  let to_dyn f { src; kind; dst; section } =
+    let open Dyn in
+    record
+      [ ("src", f src)
+      ; ("kind", dyn_of_kind kind)
+      ; ("dst", Dst.to_dyn dst)
+      ; ("section", Section.to_dyn section)
+      ]
 end
 
 module Entry_with_site = struct

src/dune_rules/install.mli

@@ -146,6 +146,8 @@ module Entry : sig
     'a t -> paths:Section.Paths.t -> prefix:Path.t -> 'a t
 
   val compare : ('a -> 'a -> Ordering.t) -> 'a t -> 'a t -> Ordering.t
+
+  val to_dyn : ('a -> Dyn.t) -> 'a t -> Dyn.t
 end
 
 (** Same as Entry, but the destination can be in the site of a package *)