patdiff: Fix patdiff-git-wrapper's shebang line

This package uses /bin/bash, which wasn't being automatically patched
because it wasn't provided bash as a build input.

pkgs/development/ocaml-modules/janestreet/0.15.nix

@@ -1,4 +1,5 @@
 { self
+, bash
 , fetchpatch
 , lib
 , openssl
@@ -487,6 +488,10 @@ with self;
   patdiff = janePackage {
     pname = "patdiff";
     hash = "0623a7n5r659rkxbp96g361mvxkcgc6x9lcbkm3glnppplk5kxr9";
+
+    # Used by patdiff-git-wrapper.  Providing it here also causes the shebang
+    # line to be automatically patched.
+    buildInputs = [ bash ];
     propagatedBuildInputs = [ core_unix patience_diff ocaml_pcre ];
     meta = {
       description = "File Diff using the Patience Diff algorithm";

pkgs/top-level/ocaml-packages.nix

@@ -1570,7 +1570,7 @@ let
     if lib.versionOlder "4.10.2" ocaml.version
     then import ../development/ocaml-modules/janestreet/0.15.nix {
       inherit self;
-      inherit (pkgs) fetchpatch lib openssl zstd;
+      inherit (pkgs) bash fetchpatch lib openssl zstd;
     }
     else if lib.versionOlder "4.08" ocaml.version
     then import ../development/ocaml-modules/janestreet/0.14.nix {