go-mingw docker image with win 7 support add pkgs for cgo: mingw-w64 version is 8.0.0, gcc version is 10.2.1 ninja-build g++-mingw-w64-i686-posix gcc-mingw-w64-i686-posix g++-mingw-w64-x86-64-posix gcc-mingw-w64-x86-64-posix cmake latest version