#ifndef _NTRTL_H
#if defined(_WIN64)
#if defined(_PHLIB_)

FORCEINLINE
NTSTATUS
NTAPI_INLINE
RtlWow64GetThreadContext(
    _In_ HANDLE ThreadHandle,
    _Inout_ PWOW64_CONTEXT ThreadContext
    )
{
    return NtQueryInformationThread(
        ThreadHandle,
        ThreadWow64Context,
        ThreadContext,
        sizeof(WOW64_CONTEXT),
        NULL
        );
}

#endif
#endif
#endif
View code on GitHub

#ifndef _NTRTL_H
#if defined(_WIN64)
#if defined(_PHLIB_)
// ...
#else

// rev
NTSYSAPI
NTSTATUS
NTAPI
RtlWow64GetThreadContext(
    _In_ HANDLE ThreadHandle,
    _Inout_ PWOW64_CONTEXT ThreadContext
    );

#endif
#endif
#endif
View code on GitHub