Make arj cross-compileable.

arj assumes that build and host are the same.
Fix those assumptions.

diff '--exclude=config.status' '--exclude=configure' '--exclude=*autom4te*' '--exclude=config.log' '--exclude=*~' -ur src-orig/gnu/configure.in src/gnu/configure.in
--- src-orig/gnu/configure.in	2017-09-08 21:45:38.474802486 +0200
+++ src/gnu/configure.in	2017-09-08 23:09:57.990014311 +0200
@@ -15,11 +15,15 @@
 AC_CONFIG_HEADER([../c_defs.h:config.h.in])
 
 dnl Checks for the canonical system name
+AC_CANONICAL_BUILD
 AC_CANONICAL_HOST
 
 dnl Checks for programs.
 AC_PROG_CC
 
+AC_CHECK_PROGS(BUILD_CC, [gcc egcs cc clang])
+test -z "$BUILD_CC" && AC_MSG_ERROR([none of gcc, egcs and cc is found. set BUILD_CC manually.])
+
 dnl Checks for header files.
 AC_HEADER_STDC
 AC_CHECK_HEADERS([fcntl.h limits.h malloc.h])
@@ -196,6 +200,7 @@
 AC_SUBST(LD_STRIP)
 AC_SUBST(REGISTER)
 AC_SUBST(TOLERANT_FNMATCH)
+AC_SUBST(BUILD_CC)
 
 AC_CONFIG_FILES([../GNUmakefile:makefile.in])
 AC_OUTPUT
diff '--exclude=config.status' '--exclude=configure' '--exclude=*autom4te*' '--exclude=config.log' '--exclude=*~' -ur src-orig/gnu/makefile.in src/gnu/makefile.in
--- src-orig/gnu/makefile.in	2017-09-08 21:45:38.474802486 +0200
+++ src/gnu/makefile.in	2017-09-08 23:17:01.790798189 +0200
@@ -14,6 +14,8 @@
 LIBS = @LIBS@
 REGISTER = @REGISTER@
 
+BUILD_CC = @BUILD_CC@
+
 # Programs
 
 INSTALL = @INSTALL@
@@ -40,17 +42,21 @@
 
 ALL_CFLAGS = -DLOCALE=LANG_$(LOCALE) -DLOCALE_DESC="\"$(LOCALE)\"" \
 	     -DPKGLIBDIR="\"$(pkglibdir)\"" @OS_DEF@
+BUILD_ALL_CFLAGS = -DLOCALE=LANG_$(LOCALE) -DLOCALE_DESC="\"$(LOCALE)\"" \
+	     -DPKGLIBDIR="\"$(pkglibdir)\"" @OS_DEF@
 
 ifndef COMMERCIAL
 PACKAGE = s
 else
 PACKAGE = c
 ALL_CFLAGS += -DCOMMERCIAL
+BUILD_ALL_CFLAGS += -DCOMMERCIAL
 endif
 
 ifdef DEBUG
 DEBUG_SM = d
 ALL_CFLAGS += -DDEBUG
+BUILD_ALL_CFLAGS += -DDEBUG
 else
 DEBUG_SM = r
 endif
@@ -62,6 +68,7 @@
 endif
 
 ALL_CFLAGS += @CPPFLAGS@ $(CPPFLAGS) @CFLAGS@ $(CFLAGS)
+BUILD_ALL_CFLAGS += $(BUILD_CPPFLAGS) $(BUILD_CFLAGS)
 
 # Build Installation paths
 
@@ -73,6 +80,7 @@
 
 TOOLS_DIR = $(BASEDIR)/tools
 ARJ_DIR = $(BASEDIR)/arj
+BUILD_ARJ_DIR = $(BASEDIR)/build-arj
 ARJSFXV_DIR = $(BASEDIR)/arjsfxv
 ARJSFX_DIR = $(BASEDIR)/arjsfx
 ARJSFXJR_DIR = $(BASEDIR)/arjsfxjr
@@ -90,8 +98,10 @@
 REQUIRES_DEF = @REQUIRES_DEF@
 
 COPT = -c -I@OUT_DIR@ -I$(BASEDIR) -I$(SRC_DIR) $(ALL_CFLAGS)
-STD_COPT = -DARJUTIL $(COPT)
+BUILD_COPT = -c -I@OUT_DIR@ -I$(BASEDIR) -I$(SRC_DIR) $(BUILD_ALL_CFLAGS)
+BUILD_STD_COPT = -DARJUTIL $(BUILD_COPT)
 ARJ_COPT = -DSFL=4 $(COPT)
+BUILD_ARJ_COPT = -DSFL=4 $(BUILD_COPT)
 ARJSFXV_COPT = -DSFL=3 $(COPT)
 ARJSFX_COPT = -DSFL=2 $(COPT)
 ARJSFXJR_COPT = -DSFL=1 $(COPT)
@@ -106,6 +116,9 @@
 $(ARJ_DIR)/%.o: $(BASEDIR)/%.c
 	$(CC) $(COPT) -o$@ $<
 
+$(BUILD_ARJ_DIR)/%.o: $(BASEDIR)/%.c
+	$(BUILD_CC) -DDISABLE_ARJCRYPT=1 $(BUILD_COPT) -o$@ $<
+
 $(ARJSFX_DIR)/%.o: $(BASEDIR)/%.c
 	$(CC) $(COPT) -o$@ $<
 
@@ -131,11 +144,14 @@
 	$(CC) $(COPT) -o$@ $<
 
 $(TOOLS_DIR)/%.o: $(SRC_DIR)/%.c
-	$(CC) $(STD_COPT) -o$@ $<
+	$(BUILD_CC) $(BUILD_STD_COPT) -o$@ $<
 
 $(ARJ_DIR)/%.o: $(SRC_DIR)/%.c
 	$(CC) $(ARJ_COPT) -o$@ $<
 
+$(BUILD_ARJ_DIR)/%.o: $(SRC_DIR)/%.c
+	$(BUILD_CC) $(BUILD_ARJ_COPT)  -DDISABLE_ARJCRYPT=1 -o$@ $<
+
 $(ARJSFXV_DIR)/%.o: $(SRC_DIR)/%.c
 	$(CC) $(ARJSFXV_COPT) -o$@ $<
 
@@ -235,22 +251,22 @@
 		filemode.o packager.o arjdata.o)
 
 $(TOOLS_DIR)/msgbind$x: $(MSGBIND_OBJS)
-	$(CC) $(ALL_CFLAGS) $(LDFLAGS) -o $@ $(MSGBIND_OBJS) $(LIBS)
+	$(BUILD_CC) $(BUILD_ALL_CFLAGS) $(BUILD_LDFLAGS) -ldl -o $@ $(MSGBIND_OBJS) $(LIBS)
 
 $(TOOLS_DIR)/today$x: $(TODAY_OBJS)
-	$(CC) $(ALL_CFLAGS) $(LDFLAGS) -o $@ $(TODAY_OBJS) $(LIBS)
+	$(BUILD_CC) $(BUILD_ALL_CFLAGS) $(BUILD_LDFLAGS) -ldl -o $@ $(TODAY_OBJS) $(LIBS)
 
 $(TOOLS_DIR)/make_key$x: $(MAKE_KEY_OBJS)
-	$(CC) $(ALL_CFLAGS) $(LDFLAGS) -o $@ $(MAKE_KEY_OBJS) $(LIBS)
+	$(BUILD_CC) $(BUILD_ALL_CFLAGS) $(BUILD_LDFLAGS) -ldl -o $@ $(MAKE_KEY_OBJS) $(LIBS)
 
 $(TOOLS_DIR)/postproc$x: $(POSTPROC_OBJS)
-	$(CC) $(ALL_CFLAGS) $(LDFLAGS) -o $@ $(POSTPROC_OBJS) $(LIBS)
+	$(BUILD_CC) $(BUILD_ALL_CFLAGS) $(BUILD_LDFLAGS) -ldl -o $@ $(POSTPROC_OBJS) $(LIBS)
 
 $(TOOLS_DIR)/join$x: $(JOIN_OBJS)
-	$(CC) $(ALL_CFLAGS) $(LDFLAGS) -o $@ $(JOIN_OBJS) $(LIBS)
+	$(BUILD_CC) $(BUILD_ALL_CFLAGS) $(BUILD_LDFLAGS) -ldl -o $@ $(JOIN_OBJS) $(LIBS)
 
 $(TOOLS_DIR)/packager$x: $(PACKAGER_OBJS)
-	$(CC) $(ALL_CFLAGS) $(LDFLAGS) -o $@ $(PACKAGER_OBJS) $(LIBS)
+	$(BUILD_CC) $(BUILD_ALL_CFLAGS) $(BUILD_LDFLAGS) -ldl -o $@ $(PACKAGER_OBJS) $(LIBS)
 
 # This rule tells that timestamping badly needs date_sig.c (it may bail out
 # otherwise when the timestamps are being created for the first time)
@@ -355,17 +371,22 @@
 # ARJ itself
 #
 
-ARJ_OBJS = $(patsubst %,$(ARJ_DIR)/%, \
-	   filemode.o date_sig.o fmsg_arj.o imsg_arj.o \
+ARJ_OBJS_BASE= filemode.o date_sig.o fmsg_arj.o imsg_arj.o \
 	   nmsg_arj.o integr.o file_reg.o decode.o encode.o \
 	   arj.o enc_gwy.o fardata.o arj_user.o arj_arcv.o \
 	   arj_file.o crc32.o misc.o debug.o arj_proc.o \
 	   environ.o ea_mgr.o uxspec.o ext_hdr.o arjtypes.o exe_sear.o chk_fmsg.o \
 	   filelist.o arjsec_h.o arjsec_l.o garble.o scrnio.o ansi.o \
 	   crc16tab.o recovery.o gost.o gost40.o gost_t.o \
-	   externs.o)
+	   externs.o
+
+ARJ_OBJS = $(patsubst %,$(ARJ_DIR)/%, $(ARJ_OBJS_BASE) )
+BUILD_ARJ_OBJS = $(patsubst %,$(BUILD_ARJ_DIR)/%, $(ARJ_OBJS_BASE) )
+
+$(BUILD_ARJ_DIR)/arj$x: $(BUILD_ARJ_OBJS)
+	$(BUILD_CC) $(BUILD_ALL_CFLAGS) $(BUILD_LDFLAGS) -ldl -o $@ $(BUILD_ARJ_OBJS)
 
-$(ARJ_DIR)/arj$x: $(ARJ_OBJS) \
+$(ARJ_DIR)/arj$x: $(ARJ_OBJS) $(BUILD_ARJ_DIR)/arj$x \
 		  $(RES_DIR)/$(LOCALE)/arjl.txt $(RES_DIR)/$(LOCALE)/arjs.txt \
 		  $(TOOLS_DIR)/join$x \
 		  $(TOOLS_DIR)/postproc$x \
@@ -380,7 +401,7 @@
 	$(TOOLS_DIR)/join $(ARJ_DIR)/arj$x $(ARJSFXV_DIR)/arjsfxv$x
 	$(TOOLS_DIR)/join $(ARJ_DIR)/arj$x $(SFXSTUB_DIR)/sfxstub$x
 	rm -f $(BASEDIR)/help.arj
-	$(ARJ_DIR)/arj$x a $(BASEDIR)/help.arj -+ -t1f -2e -e -jm -jh65535 -jt $(RES_DIR)/$(LOCALE)/arj?.txt
+	$(BUILD_ARJ_DIR)/arj$x a $(BASEDIR)/help.arj -+ -t1f -2e -e -jm -jh65535 -jt $(RES_DIR)/$(LOCALE)/arj?.txt
 	$(TOOLS_DIR)/join $(ARJ_DIR)/arj$x $(BASEDIR)/help.arj
 	$(TOOLS_DIR)/postproc $@
 
@@ -455,6 +476,7 @@
 	-mkdir -p $(ARJSFX_DIR)
 	-mkdir -p $(ARJSFXJR_DIR)
 	-mkdir -p $(ARJ_DIR)
+	-mkdir -p $(BUILD_ARJ_DIR)
 	-mkdir -p $(REARJ_DIR)
 	-mkdir -p $(REGISTER_DIR)
 	-mkdir -p $(ARJDISP_DIR)
--- src-orig/garble.c	2004-02-21 23:53:34.000000000 +0100
+++ src/garble.c	2017-10-05 15:30:09.416517680 +0200
@@ -90,6 +90,7 @@
 #if TARGET==OS2||TARGET==WIN32||TARGET==UNIX
 static void remove_arjcrypt()
 {
+#ifndef DISABLE_ARJCRYPT
  if(arjcrypt_loaded)
  {
   #if TARGET==OS2
@@ -100,6 +101,7 @@
    dlclose(arjcrypt_hmod);
   #endif
  }
+#endif
  arjcrypt_loaded=0;
 }
 #endif
@@ -109,6 +109,10 @@
 
 static int arjcrypt_init(char *name)
 {
+#ifdef DISABLE_ARJCRYPT
+  fputs("arjcrypt is disabled", new_stdout);
+  error(M_ARJCRYPT_ERROR);
+#else
  FILE *stream;
  int arjcrypt_size;                     /* Size of ARJCRYPT module */
  char *tmp_cryptmem;                    /* Temporary storage for ARJCRYPT */
@@ -186,6 +190,7 @@
   if((arjcrypt_entry=dlsym(arjcrypt_hmod, "entry"))==NULL)
    error(M_NO_ARJCRYPT_ENTRY);
  #endif
+#endif
  return(0);
 }