make bspack not relying on c stubs so that it can be running without compiling

jscomp/ext/ext_string.ml

@@ -332,7 +332,7 @@ let replace_backward_slash (x : string)=
 
 let empty = ""
 
-#if BS_BROWSER then
+#if BS_BROWSER || BS_PACK then
 let compare = Bs_hash_stubs.string_length_based_compare
 #else
 external compare : string -> string -> int = "caml_string_length_based_compare" [@@noalloc];;    

jscomp/ext/ext_string.mli

@@ -164,7 +164,7 @@ val replace_backward_slash : string -> string
 
 val empty : string 
 
-#if BS_BROWSER then
+#if BS_BROWSER || BS_PACK then
 val compare :  string -> string -> int
 #else
 external compare : string -> string -> int = "caml_string_length_based_compare" [@@noalloc];;  

jscomp/snapshot.ninja

@@ -48,7 +48,7 @@ build $SNAP/unstable/all_ounit_tests.ml: bspack | ./bin/bspack.exe $LTO
     main = Ounit_tests_main         
 
 build $SNAP/unstable/bspack.ml: bspack | ./bin/bspack.exe $LTO
-    flags = -bs-MD -module-alias Config=Config_whole_compiler  -I $OCAML_SRC_PARSING -I $OCAML_SRC_UTILS -I stubs -I ext -I common -I depends -I core -I main -bs-main Bspack_main
+    flags = -D BS_PACK=true -bs-MD -module-alias Config=Config_whole_compiler  -I $OCAML_SRC_PARSING -I $OCAML_SRC_UTILS -I stubs -I ext -I common -I depends -I core -I main -bs-main Bspack_main
     main = Bspack_main
 
 build $SNAP/unstable/js_compiler.ml: bspack | ./bin/bspack.exe $LTO

jscomp/stubs/bs_hash_stubs.ml

@@ -1,5 +1,5 @@
 
-#if BS_BROWSER then
+#if BS_BROWSER || BS_PACK then
 
 
 let hash_string : string -> int = Hashtbl.hash

lib/4.06.1/unstable/bspack.ml

@@ -7270,6 +7270,28 @@ let get_or arr i cb =
   if i >=0 && i < Array.length arr then 
     Array.unsafe_get arr i 
   else cb ()  
+end
+module Bs_hash_stubs
+= struct
+#1 "bs_hash_stubs.ml"
+
+
+
+
+let hash_string : string -> int = Hashtbl.hash
+let hash_string_int s i = Hashtbl.hash (s,i)
+let hash_string_small_int :  string -> int  -> int = hash_string_int
+let hash_stamp_and_name (i:int) (s:string) = Hashtbl.hash(i,s)
+let hash_int (i:int) = Hashtbl.hash i 
+let string_length_based_compare (x : string ) (y : string) = 
+    let len1 = String.length x in 
+    let len2 = String.length y in 
+    if len1 = len2 then String.compare x y 
+    else compare (len1:int) len2
+let int_unsafe_blit: int array -> int -> int array -> int -> int -> unit = 
+    Array.blit
+
+
 end
 module Ext_bytes : sig 
 #1 "ext_bytes.mli"
@@ -7515,7 +7537,7 @@ val replace_backward_slash : string -> string
 val empty : string 
 
 
-external compare : string -> string -> int = "caml_string_length_based_compare" [@@noalloc];;  
+val compare :  string -> string -> int
 
 val single_space : string
 
@@ -7897,7 +7919,7 @@ let replace_backward_slash (x : string)=
 let empty = ""
 
 
-external compare : string -> string -> int = "caml_string_length_based_compare" [@@noalloc];;    
+let compare = Bs_hash_stubs.string_length_based_compare
 
 let single_space = " "
 let single_colon = ":"
@@ -10826,32 +10848,6 @@ let protect_list rvs body =
     List.iter2 (fun (x,_) old -> x := old) rvs olds;
     raise e 
 
-end
-module Bs_hash_stubs
-= struct
-#1 "bs_hash_stubs.ml"
-
-
-external hash_string :  string -> int = "caml_bs_hash_string" [@@noalloc];;
-
-external hash_string_int :  string -> int  -> int = "caml_bs_hash_string_and_int" [@@noalloc];;
-
-external hash_string_small_int :  string -> int  -> int = "caml_bs_hash_string_and_small_int" [@@noalloc];;
-
-external hash_stamp_and_name : int -> string -> int = "caml_bs_hash_stamp_and_name" [@@noalloc];;
-
-external hash_small_int : int -> int = "caml_bs_hash_small_int" [@@noalloc];;
-
-external hash_int :  int  -> int = "caml_bs_hash_int" [@@noalloc];;
-
-external string_length_based_compare : string -> string -> int  = "caml_string_length_based_compare" [@@noalloc];;
-
-external    
-    int_unsafe_blit : 
-    int array -> int -> int array -> int -> int -> unit = "caml_int_array_blit" [@@noalloc];;
-
-
-
 end
 module Ext_util : sig 
 #1 "ext_util.mli"