chore: checkpoint before Python removal

vendor/poly1305/fuzz/main.rs

@@ -0,0 +1,11 @@
+#[macro_use]
+extern crate afl;
+
+fn main() {
+    fuzz!(|data: &[u8]| {
+        // Use first 32 bytes of data as key.
+        if data.len() >= 32 {
+            poly1305::fuzz_avx2((&data[0..32]).into(), &data[32..]);
+        }
+    });
+}