Auto merge of #115005 - compiler-errors:passes, r=cjgillot

Don't do intra-pass validation on MIR shims

Fixes #114375

In the test that was committed, we end up generating the drop shim for `struct Foo` that looks like:

```
fn std::ptr::drop_in_place(_1: *mut Foo) -> () {
    let mut _0: ();

    bb0: {
        goto -> bb5;
    }

    bb1: {
        return;
    }

    bb2 (cleanup): {
        resume;
    }

    bb3: {
        goto -> bb1;
    }

    bb4 (cleanup): {
        drop(((*_1).0: foo::WrapperWithDrop<()>)) -> [return: bb2, unwind terminate];
    }

    bb5: {
        drop(((*_1).0: foo::WrapperWithDrop<()>)) -> [return: bb3, unwind: bb2];
    }
}
```

In `bb4` and `bb5`, we assert that `(*_1).0` has type `WrapperWithDrop<()>`. However, In a user-facing param env, the type is actually `WrapperWithDrop<Tait>`. These types are not equal in a user-facing param-env (and can't be made equal even if we use `DefiningAnchor::Bubble`, since it's a non-local TAIT).

Author: bors