On Windows it isn't. Microsoft has made it clear that you aren't supposed to link to the msvcrt.dlls shipped in Windows. See https://sourceforge.net/p/mingw-w64/wiki2/The%20case%20again...
If I want to zero memory on Windows without libc dependencies, I use ZeroMemory() or FillMemory() and not memset().
No need to have any dependency on msvcr*.dll or the equivalent for Borland, Intel and other Windows compilers, which are effectively the Windows libc.
The argument here is that on Windows and Mac OS X, the libc library is the ‘raw OS API’ and it hence makes perfect sense to rely on it if you want to support such operating systems.