Comment 3 for bug 1943446

Ok so since gcc-11, it won't pass tests with -O3, neither O2.
Got it work with O1.
```
export DEB_CXXFLAGS_MAINT_STRIP = -O3
export DEB_CXXFLAGS_MAINT_APPEND = -O1
```

As it worked fine as is with gcc-10 on Impish, I guess it's definitely
something for the toolchain team.