Rollup merge of #89558 - lcnr:query-stable-lint, r=estebank

Add rustc lint, warning when iterating over hashmaps

r? rust-lang/wg-incr-comp

compiler/rustc_privacy/src/lib.rs

@@ -5,6 +5,7 @@
 #![feature(try_blocks)]
 #![feature(associated_type_defaults)]
 #![recursion_limit = "256"]
+#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 use rustc_ast::MacroDef;
 use rustc_attr as attr;