Rollup merge of #40520 - steveklabnik:link-core-slice, r=alexcrichton
Rollup merge of #40520 - steveklabnik:link-core-slice, r=alexcrichton

Link core::slice to std::slice

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