The attached patch adds a switch --no-instructions to initdb and pg_upgrade, which prevents them from printing instructions about how to start the cluster (initdb) or how to analyze and delete clusters (pg_upgrade).
The use case for this is for example the debian or redhat package wrappers. When these commands are run under those wrappers the printed instructions are *wrong*. It's better in that case to exclude them, and let the wrapper be responsible for printing the correct instructions.
I went with the name --no-instructions to have the same name for both initdb and pg_upgrade. The downside is that "no-instructions" also causes the scripts not to be written in pg_upgrade, which arguably is a different thing. We could go with "--no-instructions" and "--no-scripts", but that would leave the parameters different. I also considered "--no-next-step", but that one didn't quite have the right ring to me. I'm happy for other suggestions on the parameter names.