fuzz-tests: Add a test for the gossipd-connectd interface

Changelon-None: `connectd_req()` in `gossipd/gossipd.c` is
responsible for handling gossip messages from peers handed to
it by `connectd`. Add a stateful test simulating its behaviour.

Author: Chandra Pratap

tests/fuzz/Makefile

@@ -72,5 +72,21 @@ FUZZ_COMMON_OBJS := \
 $(FUZZ_TARGETS_OBJS): $(COMMON_HEADERS) $(WIRE_HEADERS) $(COMMON_SRC)
 $(FUZZ_TARGETS_BIN): $(LIBFUZZ_OBJS) $(FUZZ_COMMON_OBJS) $(BITCOIN_OBJS)
 
+tests/fuzz/fuzz-gossipd-connectd: gossipd/seeker.o			\
+				  gossipd/gossipd_wiregen.o		\
+				  gossipd/gossip_store_wiregen.o	\
+				  gossipd/gossip_store.o		\
+				  gossipd/queries.o			\
+				  gossipd/sigcheck.o			\
+				  gossipd/txout_failures.o		\
+				  common/wire_error.o			\
+				  common/gossmap.o			\
+				  common/gossip_store.o			\
+				  common/gossmods_listpeerchannels.o	\
+				  common/timeout.o			\
+				  common/fp16.o				\
+				  common/decode_array.o			\
+				  connectd/connectd_gossipd_wiregen.o
+
 ALL_C_SOURCES += $(FUZZ_TARGETS_SRC) $(LIBFUZZ_SRC)
 ALL_FUZZ_TARGETS += $(FUZZ_TARGETS_BIN)