Work on ansi and clean Makefiles

FossilOrigin-Name: 0805f78d34219a2aac597a313081ce869c389e6b5d471c65c7f43d0906c0a400

src/cw/mavl_replace_data.c

@@ -0,0 +1,12 @@
+#include "mavl.h"
+
+void *mavl_replace_data(struct mavl *t, void *data, int len)
+{
+	void *df = mavl_get(t, data);
+	if (!df)
+		return NULL;
+	memcpy(df, data, len);
+	return df;
+}
+
+