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_query_impl/src/lib.rs

@@ -8,6 +8,7 @@
 #![feature(once_cell)]
 #![feature(rustc_attrs)]
 #![recursion_limit = "256"]
+#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 #[macro_use]
 extern crate rustc_macros;