> depends: build bdb with -std=c++17
> depends: build Boost with -std=c++17
> depends: build zeromq with -std=c++17
> builds: don't pass -silent to qt when building in debug mode
>
> This means we'll get build output like this when building with DEBUG=1:
>
> g++ -c -pipe -ffunction-sections -O2 -fPIC -std=c++11 -fno-exceptions <lots more> ../../corelib/kernel/qcoreapplication.cpp
>
> rather than just:
>
> compiling ../../corelib/kernel/qcoreapplication.cpp
> depends: build qt in c++17 mode
This is a backport of core#20471
Depends on D13651