Rollup merge of rust-lang#63264 - arielb1:revert-private-coherence-errors, r=estebank

Revert "Rollup merge of rust-lang#62696 - chocol4te:fix_#62194, r=estebank"

This reverts commit df21a6f (rust-lang#62696), reversing
changes made to cc16d04.

That PR makes error messages worse than before, and we couldn't come up with a way of actually making them better, so revert it for now. Any idea for making this error message better is welcome!

Fixes rust-lang#63145.

r? @estebank

Author: Centril

src/librustc/traits/specialize/mod.rs

@@ -366,13 +366,8 @@ pub(super) fn specialization_graph_provider(
                     }
                 }
 
-                let access_levels = tcx.privacy_access_levels(impl_def_id.krate);
-                if let Some(id) = tcx.hir().as_local_hir_id(impl_def_id) {
-                    if access_levels.is_exported(id) || access_levels.is_public(id) {
-                        for cause in &overlap.intercrate_ambiguity_causes {
-                            cause.add_intercrate_ambiguity_hint(&mut err);
-                        }
-                    }
+                for cause in &overlap.intercrate_ambiguity_causes {
+                    cause.add_intercrate_ambiguity_hint(&mut err);
                 }
 
                 if overlap.involves_placeholder {

src/test/ui/coherence/coherence-overlap-upstream.old.stderr

@@ -5,6 +5,8 @@ LL | impl<T> Foo for T where T: Remote {}
    | --------------------------------- first implementation here
 LL | impl Foo for i16 {}
    | ^^^^^^^^^^^^^^^^ conflicting implementation for `i16`
+   |
+   = note: upstream crates may add new impl of trait `coherence_lib::Remote` for type `i16` in future versions
 
 error: aborting due to previous error
 

src/test/ui/coherence/coherence-overlap-upstream.re.stderr

@@ -5,6 +5,8 @@ LL | impl<T> Foo for T where T: Remote {}
    | --------------------------------- first implementation here
 LL | impl Foo for i16 {}
    | ^^^^^^^^^^^^^^^^ conflicting implementation for `i16`
+   |
+   = note: upstream crates may add new impl of trait `coherence_lib::Remote` for type `i16` in future versions
 
 error: aborting due to previous error
 

src/test/ui/coherence/coherence_copy_like_err_fundamental_struct_tuple.old.stderr

@@ -6,6 +6,8 @@ LL | impl<T: lib::MyCopy> MyTrait for T { }
 ...
 LL | impl MyTrait for lib::MyFundamentalStruct<(MyType,)> { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `lib::MyFundamentalStruct<(MyType,)>`
+   |
+   = note: upstream crates may add new impl of trait `lib::MyCopy` for type `lib::MyFundamentalStruct<(MyType,)>` in future versions
 
 error: aborting due to previous error
 

src/test/ui/coherence/coherence_copy_like_err_fundamental_struct_tuple.re.stderr

@@ -6,6 +6,8 @@ LL | impl<T: lib::MyCopy> MyTrait for T { }
 ...
 LL | impl MyTrait for lib::MyFundamentalStruct<(MyType,)> { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `lib::MyFundamentalStruct<(MyType,)>`
+   |
+   = note: upstream crates may add new impl of trait `lib::MyCopy` for type `lib::MyFundamentalStruct<(MyType,)>` in future versions
 
 error: aborting due to previous error
 

src/test/ui/coherence/coherence_copy_like_err_struct.old.stderr

@@ -6,6 +6,8 @@ LL | impl<T: lib::MyCopy> MyTrait for T { }
 ...
 LL | impl MyTrait for lib::MyStruct<MyType> { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `lib::MyStruct<MyType>`
+   |
+   = note: upstream crates may add new impl of trait `lib::MyCopy` for type `lib::MyStruct<MyType>` in future versions
 
 error: aborting due to previous error
 

src/test/ui/coherence/coherence_copy_like_err_struct.re.stderr

@@ -6,6 +6,8 @@ LL | impl<T: lib::MyCopy> MyTrait for T { }
 ...
 LL | impl MyTrait for lib::MyStruct<MyType> { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `lib::MyStruct<MyType>`
+   |
+   = note: upstream crates may add new impl of trait `lib::MyCopy` for type `lib::MyStruct<MyType>` in future versions
 
 error: aborting due to previous error
 

src/test/ui/coherence/coherence_copy_like_err_tuple.old.stderr

@@ -6,6 +6,8 @@ LL | impl<T: lib::MyCopy> MyTrait for T { }
 ...
 LL | impl MyTrait for (MyType,) { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(MyType,)`
+   |
+   = note: upstream crates may add new impl of trait `lib::MyCopy` for type `(MyType,)` in future versions
 
 error: aborting due to previous error
 

src/test/ui/coherence/coherence_copy_like_err_tuple.re.stderr

@@ -6,6 +6,8 @@ LL | impl<T: lib::MyCopy> MyTrait for T { }
 ...
 LL | impl MyTrait for (MyType,) { }
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `(MyType,)`
+   |
+   = note: upstream crates may add new impl of trait `lib::MyCopy` for type `(MyType,)` in future versions
 
 error: aborting due to previous error
 

src/test/ui/issues/issue-48728.stderr

@@ -6,6 +6,8 @@ LL | #[derive(Clone)]
 ...
 LL | impl<T: Clone + ?Sized> Clone for Node<[T]> {
    | ------------------------------------------- first implementation here
+   |
+   = note: upstream crates may add new impl of trait `std::clone::Clone` for type `[_]` in future versions
 
 error: aborting due to previous error