message: cmake: set _WIN32_WINNT for Windows 7 API
diff: @@ -383,6 +383,19 @@ if(MSVC)
  add_definitions(-D_VARIADIC_MAX=10)
  endif()
  +if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
  + get_directory_property(__DIRECTORY_COMPILE_DEFINITIONS COMPILE_DEFINITIONS)
  + if((NOT " ${CMAKE_CXX_FLAGS} ${CMAKE_CXX_FLAGS_RELEASE} ${OPENCV_EXTRA_CXX_FLAGS} ${OPENCV_EXTRA_FLAGS_RELEASE} ${__DIRECTORY_COMPILE_DEFINITIONS}" MATCHES "_WIN32_WINNT"
  + AND NOT OPENCV_CMAKE_SKIP_MACRO_WIN32_WINNT)
  + OR OPENCV_CMAKE_FORCE_MACRO_WIN32_WINNT
  + )
  + # https://docs.microsoft.com/en-us/cpp/porting/modifying-winver-and-win32-winnt
  + # Target Windows 7 API
  + set(OPENCV_CMAKE_MACRO_WIN32_WINNT "0x0601" CACHE STRING "Value of _WIN32_WINNT macro")
  + add_definitions(-D_WIN32_WINNT=${OPENCV_CMAKE_MACRO_WIN32_WINNT})
  + endif()
  +endif()
  +
  # Enable compiler options for OpenCV modules/apps/samples only (ignore 3rdparty)
  macro(ocv_add_modules_compiler_options)
  if(MSVC AND NOT OPENCV_SKIP_MSVC_W4_OPTION)
  