Rollup merge of #29865 - apasel422:mutex, r=alexcrichton
Rollup merge of #29865 - apasel422:mutex, r=alexcrichton

r? @alexcrichton

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