This is the response I sent back - for better or worse.
Pthreads-win32 is distributed under the Lesser GNU Public License and is
free and open source software. It contains no encryption or decryption
code or references, so it is very unlikely that it would require an
export/re-export license. The source code and executable versions of it
have been available unrestricted for over 10 years via a public web site
in the US and is mirrored in many countries outside of North America and
Europe and so far this question hasn't arisen before to my knowledge.
It provides nothing more than an alternative means of calling the
threading API already available in every version of Microsoft Windows,
so I would expect that it may be exported to anywhere that Microsoft
Windows may be exported. It's purpose is to provide source code
compatibility with the threading API that exists in every version of
Unix or Linux.