qos-test fails when built with LTO and gcc-12
Description of problem:
The issue is already discussed here [1]. I'm simply building latest QEMU release and running the test suite. I thought the issue was fixed in 7.0 but it has resurfaced. Do QEMU dev's not build with LTO? I'm not able to debug this but I can test any proposed fixes etc. Thanks.

[1] https://lore.kernel.org/all/1d3bbff9e92e7c8a24db9e140dcf3f428c2df103.camel@suse.com/
Steps to reproduce:
1. Build QEMU with gcc-12 and LTO enabled
2. Run make check
3. Observe test suite failures in qos-test
Additional information:
```
Summary of Failures:

  2/265 qemu:qtest+qtest-aarch64 / qtest-aarch64/qos-test                  ERROR           0.59s   killed by signal 6 SIGABRT
  3/265 qemu:qtest+qtest-i386 / qtest-i386/qos-test                        ERROR           0.22s   killed by signal 6 SIGABRT
  7/265 qemu:qtest+qtest-x86_64 / qtest-x86_64/qos-test                    ERROR           0.40s   killed by signal 6 SIGABRT
```