move tsearch.c to autodetection for libroken.la

cf/roken-frag.m4

@@ -201,7 +201,6 @@ AC_CHECK_FUNCS([				\
 	sysctl					\
 	tdelete					\
 	tfind					\
-	tsearch					\
 	twalk					\
 	uname					\
 	unvis					\
@@ -375,6 +374,7 @@ AC_BROKEN([					\
 	strtok_r				\
 	strupr					\
 	swab					\
+	tsearch					\
 	timegm					\
 	unsetenv				\
 	verr					\

lib/roken/Makefile.am

@@ -41,7 +41,7 @@ LDADD = libroken.la
 make_roken_LDADD = 
 
 noinst_LTLIBRARIES = libtest.la
-libtest_la_SOURCES = strftime.c strptime.c snprintf.c
+libtest_la_SOURCES = strftime.c strptime.c snprintf.c tsearch.c
 libtest_la_CFLAGS = -DTEST_SNPRINTF -DTEST_STRPFTIME
 
 parse_reply_test_SOURCES = parse_reply-test.c resolve.c
@@ -111,7 +111,6 @@ libroken_la_SOURCES =		\
 	strerror_r.c		\
 	strpool.c		\
 	timeval.c		\
-	tsearch.c		\
 	tm2time.c		\
 	unvis.c			\
 	verify.c		\