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)).
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