Merge #7702

7702: Remove use of deprecated `std::collections::Bound` r=Veykril a=bstrie

`std::collections::Bound` has been deprecated since Rust 1.26, but due to a bug (rust-lang/rust#82080) it never triggered a visible deprecation warning. Fixing this is being done in rust-lang/rust#82122 , but landing that requires rustc-analyzer to build without triggering any deprecation warnings (https://github.com/rust-lang-ci/rust/runs/1911884006#step:24:19361).

Co-authored-by: bstrie <[email protected]>

Author: bors[bot]

crates/proc_macro_srv/src/rustc_server.rs

@@ -10,9 +10,10 @@
 
 use crate::proc_macro::bridge::{self, server};
 
-use std::collections::{Bound, HashMap};
+use std::collections::HashMap;
 use std::hash::Hash;
 use std::iter::FromIterator;
+use std::ops::Bound;
 use std::str::FromStr;
 use std::{ascii, vec::IntoIter};