unsafe precondition(s) violated: slice::from_raw_parts requires the pointer to be aligned and non-null in `::get_elements`

[anatawa12]

According to https://linux.die.net/man/3/tcl_listobjgetelements

If the list is empty, 0 is stored at objcPtr and NULL at objvPtr

Therefore, we need to use dangling pointer for data pointer of slice::from_raw_parts but it doesn't

tcltk/tcl/src/list.rs

Line 100 in 380a66c

slice::from_raw_parts( objv, objc as usize )