Theos [0] has been used with Linux before but I have never personally done so. I don't think anybody has yet ported ld64/codesign to run natively on Linux but it has been possible for some time to run the Mac CLI dev tools under Linux using runtime shims like maloader [1] or its descendant Darling [2].
maloader and Darling won't, they require Linux. LLVM works fine on Windows. I'm guessing the RoboVM front-end is also fairly portable. The effort to port ld64/codesign to Windows would probably be similar to the effort to port them to Linux.