Do not consider synthesized RPITITs on missing items checks
Without this patch for `tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.rs` we get ...
```
warning: the feature `return_position_impl_trait_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
--> tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.rs:4:12
|
4 | #![feature(return_position_impl_trait_in_trait)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
= note: `#[warn(incomplete_features)]` on by default
error[E0046]: not all trait items implemented, missing: `foo`, ``
--> tests/ui/impl-trait/in-trait/dont-project-to-rpitit-with-no-value.rs:12:1
|
8 | fn foo(&self) -> impl Sized;
| ----------------------------
| | |
| | `` from trait
| `foo` from trait
...
12 | impl MyTrait for i32 {
| ^^^^^^^^^^^^^^^^^^^^ missing `foo`, `` in implementation
error: aborting due to previous error; 1 warning emitted
For more information about this error, try `rustc --explain E0046`.
```
instead of ...
```
warning: the feature `return_position_impl_trait_in_trait` is incomplete and may not be safe to use and/or cause compiler crashes
--> $DIR/dont-project-to-rpitit-with-no-value.rs:4:12
|
LL | #![feature(return_position_impl_trait_in_trait)]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information
= note: `#[warn(incomplete_features)]` on by default
error[E0046]: not all trait items implemented, missing: `foo`
--> $DIR/dont-project-to-rpitit-with-no-value.rs:12:1
|
LL | fn foo(&self) -> impl Sized;
| ---------------------------- `foo` from trait
...
LL | impl MyTrait for i32 {
| ^^^^^^^^^^^^^^^^^^^^ missing `foo` in implementation
error: aborting due to previous error; 1 warning emitted
For more information about this error, try `rustc --explain E0046`.
```
r? `@compiler-errors`
031640ccd2