You are right, it did not check the `warn` lines. I've changed the duplicated type bound warnings to a lint in order to be able to turn the warnings into error messages.

But I'm not sure what `NodeId` to use for the lint (https://github.com/mozilla/rust/pull/12611/files#diff-9dc7b5d90d17fc61cb7e8522b809e21cR1032).
Using `trait_ref.def_id.node` resulted in an compiler error because of an invalid node for ` fn test_duplicated_builtin_bounds_fn<T: Eq+Ord+Eq>(&self);`