MSVC: impossible to add lib in CMAKE_C_STANDARD_LIBRARIES_INIT
CMAKE_C_STANDARD_LIBRARIES_INIT is set here https://gitlab.kitware.com/cmake/cmake/-/blob/v3.17.1/Modules/Platform/Windows-MSVC.cmake#L215
I believe the string should be appended (not set) because it prevents us from adding any custom libraries from a toolchain file.
The behavior is similar in ARTOS-GNU-C.cmake and Windows-GNU.cmake. It seems this variable is not set anywhere else.