Add more performance-relevant settings for macOS

[TomTheBear]

The current macOS support contains the basic information about CPU, caches and software environment but no real performance-relevant setting. All info I found in the www are about network tuning and extending shared memory regions:

• https://docs.tibco.com/pub/str/latest/doc/html/tuning/tuneapp.html
• https://blog.josephscott.org/2004/07/06/tweaking-mac-os-x-sysctl-values/
• https://www.heise.de/ct/hotline/Mac-OS-X-Tuning-314260.html
• https://docstore.mik.ua/orelly/unix3/mac/ch08_02.htm

What are performance-relavant settings and how to get them?