[tests][interop] fix sockets.def placement closer to test (fix build)

backend.native/tests/interop/basics/sockets.def

@@ -0,0 +1,12 @@
+headers = sys/socket.h sys/errno.h netdb.h stdio.h string.h unistd.h stdlib.h netinet/in.h
+compilerOpts.osx = -D_ANSI_SOURCE -D_POSIX_SOURCE
+excludeFunctions.osx = addrsel_policy_init
+---
+
+static int interop_errno() {
+        return errno;
+}
+
+static short interop_htons(short x) {
+	return htons(x);
+}