[fuzz] Fix stream_decompress timeouts

tests/fuzz/fuzz_data_producer.c

@@ -66,6 +66,10 @@ size_t FUZZ_dataProducer_remainingBytes(FUZZ_dataProducer_t *producer){
     return producer->size;
 }
 
+int FUZZ_dataProducer_empty(FUZZ_dataProducer_t *producer) {
+    return producer->size == 0;
+}
+
 size_t FUZZ_dataProducer_contract(FUZZ_dataProducer_t *producer, size_t newSize)
 {
     newSize = newSize > producer->size ? producer->size : newSize;