compression.h(781,53): warning C4267: 'argument': conversion from 'size_t' to 'uLong', possible loss of data

[theolivenbaum]

I'm trying to fix our build pipeline for Windows since the release 7.0.1, and hitting an issue with the warning C4267 treated as error.

It seems like the offending line was introduced by this commit: 926ee13

  // Get an upper bound on the compressed size.
  size_t upper_bound = deflateBound(&_stream, length);
  output->resize(output_header_len + upper_bound);

I'll disable the warning for now, but I assume this would better be fixed in the code.