Back out switching from libreadline to libedit:

1) It is capabilities degradation: f.e. libedit can't process ~/.inputrc files
2) It have no sense to try to un-GNU GNU program.

gnu/usr.bin/bc/Makefile

@@ -8,8 +8,8 @@ PROG=	bc
 SRCS=	bc.y execute.c global.c load.c main.c scan.l storage.c util.c \
 	number.c getopt.c getopt1.c
 CFLAGS+=-I. -I${.CURDIR} -I${.CURDIR}/../../../contrib/bc/h -DHAVE_CONFIG_H
-DPADD=	${LIBEDIT} ${LIBTERMCAP}
-LDADD=	-ledit -ltermcap
+DPADD=  ${LIBREADLINE} ${LIBTERMCAP}
+LDADD=  -lreadline -ltermcap
 
 EXAMPLES=	ckbook.b pi.b primes.b twins.b
 EXAMPDIR=	/usr/share/examples/bc

gnu/usr.bin/bc/config.h

@@ -41,10 +41,10 @@
 #define BC_COPYRIGHT "Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc."
 
 /* Define to use the readline library. */
-/* #define READLINE 1 */
+#define READLINE 1
 
 /* Define to use the BSD libedit library. */
-#define LIBEDIT 1
+/* #define LIBEDIT 1 */
 
 /* Define to `size_t' if <sys/types.h> and <stddef.h> don't define.  */
 /* #undef ptrdiff_t */