message: [Trivial] Add a comment on the use of prevector in script.
  backports bitcoin@08f71c29ea586f41d0ec3ba77f2366c41e861354
diff: @@ -363,6 +363,12 @@ private:
  int64_t m_value;
  };
  +/**
  + * We use a prevector for the script to reduce the considerable memory overhead
  + * of vectors in cases where they normally contain a small number of small elements.
  + * Tests in October 2015 (bitcoin) showed use of this reduced dbcache memory usage by 23%
  + * and made an initial sync 13% faster.
  + */
  typedef prevector<28, unsigned char> CScriptBase;
  /** Serialized script, used inside transaction inputs and outputs */
  