64-bit libunbound libraries for Windows

[ѽ҉ᶬḳ℠]

Hi,

for the development of a Thunderbird (v60+) 64-bit for WIN to validate
DNSSEC it would require a 64-bit libunbound DLL that exposes the
libunbound function calls.

Looked into the unbound package for WIN but could not trace such DLL,
that is except perhaps for System.dll. Is this the libunbound library
for WIN 64-bit systems and would it expose libunbound function calls to
a TB extension?