Get the tests working with liburcu

Mostly a few qp-trie details to adjust.

fuzz/Makefile.am

@@ -6,6 +6,7 @@ AM_CFLAGS +=				\
 AM_CPPFLAGS +=				\
 	$(LIBISC_CFLAGS)		\
 	$(LIBDNS_CFLAGS)		\
+	$(LIBURCU_CFLAGS)		\
 	$(LIBUV_CFLAGS)			\
 	-DFUZZDIR=\"$(abs_srcdir)\"	\
 	-I$(top_srcdir)/lib/dns		\

fuzz/dns_qp.c

@@ -16,10 +16,10 @@
 #include <stdbool.h>
 #include <stdint.h>
 
-#include <isc/qsbr.h>
 #include <isc/random.h>
 #include <isc/refcount.h>
 #include <isc/rwlock.h>
+#include <isc/urcu.h>
 #include <isc/util.h>
 
 #include <dns/qp.h>