cmake/mingw-w64.cmake

# cmake -DCMAKE_TOOLCHAIN_FILE=mingw-w64.cmake
set(CMAKE_SYSTEM_NAME  Windows)
set(CMAKE_C_COMPILER   x86_64-w64-mingw32-gcc)
set(CMAKE_CXX_COMPILER x86_64-w64-mingw32-g++)
set(CMAKE_RC_COMPILER  x86_64-w64-mingw32-windres)