add additional flag used by irony mode to cooperate with clang on windows
add additional flag used by irony mode to cooperate with clang on windows

lukasz-m-maciejewski/papuc_exercises,lukasz-m-maciejewski/papuc_exercises,NadzwyczajnaGrupaRobocza/papuc_exercises,NadzwyczajnaGrupaRobocza/papuc_exercises