Remove ipc_test.

This doesn't seem to be useful any more, and it's not really worth the
effort to keep updating it every time relevant dependencies or calling
signatures in the shared memory or semaphore code change.

Author: robertmhaas

src/backend/port/Makefile

@@ -42,10 +42,6 @@ else
 	$(CC) $(CFLAGS) -c $<
 endif
 
-# IPC test program
-ipc_test: ipc_test.o pg_sema.o pg_shmem.o
-	$(CC) $(CFLAGS) $(LDFLAGS) $(LDFLAGS_EX) $(export_dynamic) $^ $(LIBS) -o $@
-
 distclean clean:
 	rm -f ipc_test ipc_test.o tas_cpp.s
 	$(MAKE) -C darwin clean