KDE Illegal Instruction

Filing just for the sake of completeness.

```
iPad-Pro:~# startplasma-x11
Illegal instruction
iPad-Pro:~# dmesg
[ 0.000000] 3 stub syscall 375
653 stub syscall 375
653 stub syscall 375
664 illegal instruction at 0xf79d6a11: 0f 16 44 24 08 0f 11 46
694 stub syscall 375
694 stub syscall 375
705 illegal instruction at 0xf79d6a11: 0f 16 44 24 08 0f 11 46
713 stub syscall 375
713 stub syscall 375
724 illegal instruction at 0xf79d6a11: 0f 16 44 24 08 0f 11 46
727 illegal instruction at 0xf79d6a11: 0f 16 44 24 08 0f 11 46
```

Reproduce the failure by running startplasma-x11 and inspect the corresponding dmesg output, especially the illegal-instruction bytes and stub syscall messages. Trace which component emits the failure and determine the compatibility issue; done means KDE starts without the reported illegal-instruction crashes.

Written by the indexing model from the issue text.