Rollup merge of #29165 - iajrz:patch-1, r=steveklabnik
Rollup merge of #29165 - iajrz:patch-1, r=steveklabnik

To augment the didactic effect, made placed the thread::sleep_ms call in the last example, so that there will be time for the other locks to happen; without this, I was unable to observe the deadlock in over 1,000 runs when there was no left-handed philosopher.

GBGamer/rust,graydon/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,aidancully/rust,GBGamer/rust