Crate fails to link on Windows with GNU ABI

[ruuda]

The PrefetchVirtualMemory function requires at least a Windows 8 version of kernel32.

To compile an application that calls this function, define _WIN32_WINNT as _WIN32_WINNT_WIN8 or higher.

Apparently the GCC linker is linking against a different kernel32 that does not contain this function, resulting in an undefined symbol.