clang++: unknown argument: '-permissive-' and unsupported '-Zc:__cplusplus'

The problem nyanpasu64 mentioned in https://bugreports.qt.io/browse/QTBUG-88944 is still existing.

00:00:35.113 clang++: error: unknown argument: '-permissive-'
00:00:35.113 clang++: error: unsupported use of internal gcc -Z option '-Zc:__cplusplus'

We are using `-DCMAKE_CXX_COMPILER=C:/LLVM/bin/clang++.exe ` to configure our projekt using a Qt built with MSVC.