Rollup merge of #68378 - billyrieger:btreemap-remove-entry, r=KodrAus
Rollup merge of #68378 - billyrieger:btreemap-remove-entry, r=KodrAus

Add BTreeMap::remove_entry

Implements https://github.com/rust-lang/rust/issues/66714.

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