I kept the differences as they were in the build manifests. The differences come from 7932020f (Fix freebsd build on srht., 2020-12-28) and me copying the FreeBSD configuration to OpenBSD. We can investigate and clean this up later.
I also added another stage which builds with -flto. In my experience this can catch some errors with code shared between TUs. I also added -O2 to CFLAGS to make sure the compiler runs some optimization stages which is needed to generate certain warnings. I kept the script in .builds. As we have some more scripts which are aimed at developers it might be a good idea to create some dev directory to collect all the scripts. If we get some consensus here I can add a commit for this and send a v2. I kept the commit which Oswald thinks is redundant. While I generally agree, in that case the intent is to give a summary of the code so that I don't have to decipher the sed statement when skimming the code. I'm open to removing it depending on the mood here, though.
