Most Qt 5.15.3 tools (uic, lupdate, lrelease, …): Illegal instruction

Most Qt command line tools (also GUI tools like designer, but I can‘t use those anyway due to a missing Xserver, I guess…) like uic, lupdate and lrelease immediately result in an „Illegal instruction“ and terminate right after invocation (also with „zero input“).

Examples:

```
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly# /usr/lib/qt5/bin/qdoc
Illegal instruction
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly# /usr/lib/qt5/bin/uic
Illegal instruction
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly# /usr/lib/qt5/bin/lrelease
Illegal instruction
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly# /usr/lib/qt5/bin/designer
Illegal instruction
```

Other tools like qmake seem to work though:

```
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly# /usr/lib/qt5/bin/qmake -v
QMake version 3.1
Using Qt version 5.15.3 in /usr/lib
```

This is on a fresh iSH installation from yesterday (wiped and re-installed from the App Store):

* iPadOS 15.3.1 (latest at the time of this writing)
* IPad Air, 3rd generation (64 GB)

```
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly# uname -a
Linux Olis-Airbag 4.20.69-ish iSH 1.2.3 (298) Dec 17 2021 06:08:24 i686 Linux
```

The Qt 5.15.3 development tools had been installed with:

```
apk add qt5-qtbase-dev
```

(Plus other tools like cmake, g++, make, git)

I have not changed any package repositories (I currently wouldn‘t even know where/how), so I believe most everything else is „plain vanilla iSH“.

Here is what I believe is the relevant dmesg output, for the failed command „uic“:

```
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly# /usr/lib/qt5/bin/uic
Illegal instruction
```

dmesg output:

```
…
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 stub syscall 383
73 illegal instruction at 0xf7bad02d: 0f 16 44 24 08 0f 11 46
8 stub syscall 383
8 stub syscall 383
8 stub syscall 383
8 stub syscall 383
8 stub syscall 383
8 stub syscall 383
74 stub syscall 383
74 stub syscall 383
74 stub syscall 383
74 stub syscall 383
74 stub syscall 383
74 stub syscall 383
Olis-Airbag:/home/tknoll/resources/work/Qt/SkyDolly#
```

Start by reproducing the failure with /usr/lib/qt5/bin/uic, qdoc, lupdate, lrelease, and designer in the reported iSH environment, then compare those results with qmake -v. Use the provided uname -a and dmesg output as the initial diagnostic context; done means identifying the cause of the illegal instruction and confirming corrected behavior for the affected tools.

Written by the indexing model from the issue text.