Auto merge of #3818 - phansch:update_changelog, r=oli-obk
Auto merge of #3818 - phansch:update_changelog, r=oli-obk

Update changelog for Rust 1.33

None

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