Send payload more than 2GB

[leo-987]

Please use this template for reporting suspected bugs or requests for help.

Issue description

Send a large payload more than 2GB, zmq::tcp_write will abort, because the type of return value is int.

Environment

• libzmq version (commit hash if unreleased): 4.3.4

What's the actual result? (include assertion message & call stack if applicable)

send return BAD ADDRESS

What's the expected result?

send return 0