include dummied-out dlopen and dlsym functions for static binaries

these don't work (or do anything at all) but at least make it possible
to static link programs that insist on "having" dynamic loading
support...as long as they don't actually need to use it.

adding real support for dlopen/dlsym with static linking is going to
be significantly more difficult...

src/ldso/dynlink.c

@@ -674,6 +674,16 @@ void *__dlsym(void *p, const char *s, void *ra)
 	pthread_rwlock_unlock(&lock);
 	return res;
 }
+#else
+void *dlopen(const char *file, int mode)
+{
+	return 0;
+}
+void *__dlsym(void *p, const char *s, void *ra)
+{
+	return 0;
+}
+#endif
 
 char *dlerror()
 {
@@ -684,4 +694,3 @@ int dlclose(void *p)
 {
 	return 0;
 }
-#endif