Code highlighting breaks when setting some compiler flags in a CMake project

When setting "unusual" compiler options in a CMake project, either by setting CMAKE_CXX_FLAGS or through add_compile_options, code highlight breaks.

This has been tested with /experimental:external and /justamadeupoption, both produced the same result. Other flags such as /W0 don't break code highlighting.

See screenshots below for reference.

Possibly related to QTCREATORBUG-18768