well, slap me. I found it myself. Had to add

EXTERN_C void xs_init (pTHX);

EXTERN_C void boot_DynaLoader (pTHX_ CV* cv);

EXTERN_C void
xs_init(pTHX)
{
    char *file = __FILE__;
    dXSUB_SYS;

    /* DynaLoader is a special case */
    newXS("DynaLoader::boot_DynaLoader", boot_DynaLoader, file);
}
[download]

Found in perlembed pod!