added missing CheckIfNinjaSupportsFortran.cmake

# ninja-build<1.10 does not support fortran.

if(CMAKE_GENERATOR STREQUAL "Ninja")

  set(CMAKE_GENERATOR_SUPPORT_FORTRAN FALSE)

  execute_process(COMMAND "${CMAKE_MAKE_PROGRAM}" --version

    OUTPUT_VARIABLE NINJA_VERSION

    OUTPUT_STRIP_TRAILING_WHITESPACE

    RESULT_VARIABLE _Ninja_version_result

  )

  if(_Ninja_version_result)

    message(WARNING "Unable to determine ninja version: ${_Ninja_version_result}, assuming fortran isn't supported")

  elseif(NINJA_VERSION VERSION_LESS "1.10")

    message(WARNING "Ninja build tool too old, to compile Fortran code, please install ninja-1.10 or newer")

  else()

    set(CMAKE_GENERATOR_SUPPORT_FORTRAN TRUE)

  endif()

else()

  set(CMAKE_GENERATOR_SUPPORT_FORTRAN TRUE)

  if(NOT CMAKE_GENERATOR STREQUAL "Unix Makefiles")

    message(WARNING "Assuming fortran is supported for ${CMAKE_GENERATOR}")

  endif()

endif()