Bug#944593: patch for pxp ftbfs

[Christopher Cramer <tsuyoshi@yumegakanau.org>]

The following patch fixes this problem.

diff --git a/src/pxp-engine/pxp_lexing.mli b/src/pxp-engine/pxp_lexing.mli
index 5dc3497..ffa6e34 100644
--- a/src/pxp-engine/pxp_lexing.mli
+++ b/src/pxp-engine/pxp_lexing.mli
@@ -10,11 +10,11 @@
 
 type lexbuf = Lexing.lexbuf
 
-val from_channel : in_channel -> lexbuf
+val from_channel : ?with_positions:bool -> in_channel -> lexbuf
 
-val from_string : string -> lexbuf
+val from_string : ?with_positions:bool -> string -> lexbuf
 
-val from_function : (Bytes.t -> int -> int) -> lexbuf
+val from_function : ?with_positions:bool -> (Bytes.t -> int -> int) -> lexbuf
 
 val lexeme : lexbuf -> string
 
diff --git a/tools/src/odoc/Makefile b/tools/src/odoc/Makefile
index 071bf8d..67dbeb4 100644
--- a/tools/src/odoc/Makefile
+++ b/tools/src/odoc/Makefile
@@ -3,7 +3,7 @@ include $(TOP_DIR)/Makefile.rules
 
 SRC = chtml.ml
 OBJ = $(SRC:.ml=.cmo)
-OCAMLC_OPTIONS += -I +ocamldoc
+OCAMLC_OPTIONS += -I +ocamldoc -I +compiler-libs
 CLEAN_LIST += chtml.ml
 
 .PHONY: all
diff --git a/tools/src/odoc/chtml_ocaml4.ml b/tools/src/odoc/chtml_ocaml4.ml
index dbf8caf..667930f 100644
--- a/tools/src/odoc/chtml_ocaml4.ml
+++ b/tools/src/odoc/chtml_ocaml4.ml
@@ -34,7 +34,7 @@ open Printf
 open Odoc_info
 open Module
 
-module StringSet = Odoc_html.StringSet
+module StringSet = Odoc_html.String.Set
 
 
 let word_re = Str.regexp "[ \t\r\n]+"