We use Intel oneAPI 2023.2.0 on Windows with VS2019 installed and found out that icx supports the -external:I option for suppressing warnings from includes which came from these paths.
We use Ninja generator on Windows.
Unfortunately we have to set manually
set ( CMAKE_INCLUDE_SYSTEM_FLAG_C -external:I )
set ( CMAKE_INCLUDE_SYSTEM_FLAG_CXX -external:I )
since these are empty after CMake configure.
So I would ask if this can be fixed in CMake the future.