IAR-CXX: CMAKE_CXX_FLAGS_INIT ignored since v3.22.0-rc1
Original the IAR-CXX.cmake modul set the CMAKE_IAR_CXX_FLAG which is applied unconditionally as the first flag. since a9073db7 CMAKE_IAR_CXX_FLAG is no longer set but instead CMAKE_CXX_FLAGS, which precents to adopt CMAKE_CXX_FLAGS_INIT from the toolcahain.cmake file
After moving back to setting CMAKE_IAR_CXX_FLAG and not touch CMAKE_CXX_FLAGS everything works again, even with the latest 3.25.0-rc2