Auto merge of #99058 - michaelwoerister:remove-stable-set-and-map, r=nagisa

Remove the unused StableSet and StableMap types from rustc_data_structures.

The current implementation is not "stable" in the same sense that `HashStable` and `StableHasher` are stable, i.e. across compilation sessions. So, in my opinion, it's better to remove those types (which are basically unused anyway) than to give the wrong impression that these are safe for incr. comp.

I plan to provide new "stable" collection types soon that can be used to replace `FxHashMap` and `FxHashSet` in query results (see [draft](https://github.com/michaelwoerister/rust/commit/69d03ac7a7d651a397ab793e9d78f8fce3edf7a6)). It's unsound that `HashMap` and `HashSet` implement `HashStable` (see https://github.com/rust-lang/rust/issues/98890 for a recent P-critical bug caused by this) -- so we should make some progress there.

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_errors/src/diagnostic.rs b/compiler/rustc_errors/src/diagnostic.rs
index ba888d77b15..2a4f609a2d8 100644
--- a/compiler/rustc_errors/src/diagnostic.rs
+++ b/compiler/rustc_errors/src/diagnostic.rs
@@ -3,7 +3,7 @@ use crate::{
     CodeSuggestion, DiagnosticMessage, EmissionGuarantee, Level, LintDiagnosticBuilder, MultiSpan,
     SubdiagnosticMessage, Substitution, SubstitutionPart, SuggestionStyle,
 };
-use rustc_data_structures::stable_map::FxHashMap;
+use rustc_data_structures::fx::FxHashMap;
 use rustc_error_messages::FluentValue;
 use rustc_hir as hir;
 use rustc_lint_defs::{Applicability, LintExpectationId};