mingw-w64-crt/intrincs/fiberdata.c - mingw-w64 - Git at Google

 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN
 #endif
 #define __CRT__NO_INLINE
 #include <windows.h>

  PVOID GetFiberData(VOID)
  {
    return *(PVOID *)GetCurrentFiber();
  }
	#ifndef WIN32_LEAN_AND_MEAN
	#define WIN32_LEAN_AND_MEAN
	#endif
	#define __CRT__NO_INLINE
	#include <windows.h>

	PVOID GetFiberData(VOID)
	{
	return (PVOID )GetCurrentFiber();
	}