Rollup merge of #139345 - smoelius:into-iter-stability, r=lcnr

Extend `QueryStability` to handle `IntoIterator` implementations

This PR extends the `rustc::potential_query_instability` lint to check values passed as `IntoIterator` implementations.

Full disclosure: I want the lint to warn about this line (please see #138871 for why): aa8f0fd716/src/librustdoc/json/mod.rs (L261)

However, the lint warns about several other lines as well.

Final note: the functions `get_callee_generic_args_and_args` and `get_input_traits_and_projections` were copied directly from [Clippy's source code](4fd8c04da0/src/tools/clippy/clippy_lints/src/methods/unnecessary_to_owned.rs (L445-L496)).

compiler/rustc_errors/src/emitter.rs

@@ -17,7 +17,7 @@ use std::path::Path;
 use std::sync::Arc;
 
 use derive_setters::Setters;
-use rustc_data_structures::fx::{FxHashMap, FxIndexMap, FxIndexSet};
+use rustc_data_structures::fx::{FxIndexMap, FxIndexSet};
 use rustc_data_structures::sync::{DynSend, IntoDynSyncSend};
 use rustc_error_messages::{FluentArgs, SpanLabel};
 use rustc_lexer;
@@ -1853,7 +1853,7 @@ impl HumanEmitter {
                             && line_idx + 1 == annotated_file.lines.len(),
                     );
 
-                    let mut to_add = FxHashMap::default();
+                    let mut to_add = FxIndexMap::default();
 
                     for (depth, style) in depths {
                         // FIXME(#120456) - is `swap_remove` correct?