Build certutil for Windows

Right now, certutil is built for all platforms in Tor's rbm-based build scripts, but the certutil binary is only copied to the output directory on Linux targets. Mozilla doesn't currently distribute official certutil binaries for Windows, and there's a significant demand for reproducibly built certutil Windows binaries. Would Tor accept a patch that copies certutil to the output directory on Windows?

(I have a draft version of such a patch, and I can confirm that the resulting certutil works properly on Windows.)