Rollup merge of #92584 - lcnr:query-stable-lint, r=estebank

add rustc lint, warning when iterating over hashmaps 2

first introduced in #89558 and reverted in #90380 due to its perf impact

r? ``@estebank``

Author: matthiaskrgr

compiler/rustc_ast_lowering/src/lib.rs

@@ -34,6 +34,7 @@
 #![feature(box_patterns)]
 #![feature(never_type)]
 #![recursion_limit = "256"]
+#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 use rustc_ast::token::{self, Token};
 use rustc_ast::tokenstream::{CanSynthesizeMissingTokens, TokenStream, TokenTree};

compiler/rustc_ast_passes/src/lib.rs

@@ -8,6 +8,7 @@
 #![feature(box_patterns)]
 #![feature(let_else)]
 #![recursion_limit = "256"]
+#![cfg_attr(not(bootstrap), allow(rustc::potential_query_instability))]
 
 pub mod ast_validation;
 pub mod feature_gate;