Auto merge of #104455 - the8472:dont-drain-on-drop, r=Amanieu

Don't drain-on-drop in DrainFilter impls of various collections.

This removes drain-on-drop behavior from various unstable DrainFilter impls (not yet for HashSet/Map) because that behavior [is problematic](rust-lang/rust#43244 (comment)) (because it can lead to panic-in-drop when user closures panic) and may become forbidden if [this draft RFC passes](rust-lang/rfcs#3288).

closes #101122

[ACP](rust-lang/libs-team#136)

affected tracking issues
* #43244
* #70530
* #59618

Related hashbrown update: rust-lang/hashbrown#374

Author: bors

tests/pass/btreemap.rs

@@ -1,7 +1,7 @@
 //@revisions: stack tree
 //@[tree]compile-flags: -Zmiri-tree-borrows
 //@compile-flags: -Zmiri-strict-provenance
-#![feature(btree_drain_filter)]
+#![feature(btree_extract_if)]
 use std::collections::{BTreeMap, BTreeSet};
 use std::mem;
 
@@ -49,8 +49,8 @@ pub fn main() {
     }
     test_all_refs(&mut 13, b.values_mut());
 
-    // Test forgetting the drain.
-    let mut d = b.drain_filter(|_, i| *i < 30);
+    // Test forgetting the extractor.
+    let mut d = b.extract_if(|_, i| *i < 30);
     d.next().unwrap();
     mem::forget(d);
 }