QNX: CMake doesn't search after q++ for C++ compiler name
CMake 3.20 searches only after QCC
as the C++ compiler name for QNX.
QNX 7.0, 7.1 have the q++
as the name of the C++ compiler. See http://www.qnx.com/developers/docs/7.1/index.html#com.qnx.doc.neutrino.utilities/topic/q/qcc.html