We don't support it any more. I don't think it has ever properly
compiled Qt 6 (and it's no longer working for me against GCC 12's
libstdc++ headers). If you report a bug against it, Intel support's
first question is if you can try instead the new Clang/LLVM-based oneAPI
C++ compiler.
So we support only that one, which identifies itself as Q_CC_CLANG.
Change-Id: I5ff8e16fcdcb4ffd9ab6fffd16eb57a092c8439e
Reviewed-by: Marc Mutz <marc.mutz@qt.io>