rebase and update fixed crashes

Author: lcnr

Diff for: tests/crashes/118987.rs

@@ -1,4 +1,5 @@
-//@ known-bug: #118987
+//@ check-pass
+// Regression test for #118987 which previously caused an ICE.
 #![feature(specialization)] //~ WARN the feature `specialization` is incomplete
 
 trait Assoc {
@@ -14,4 +15,6 @@ impl Assoc for u8 {}
 trait Foo {}
 
 impl Foo for <u8 as Assoc>::Output {}
-impl Foo for <u16 as Assoc>::Output {}
+impl Foo for u16 {}
+
+fn main() {}

Diff for: tests/crashes/119272.rs

@@ -0,0 +1,12 @@
+warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
+  --> $DIR/coherence-ice-issue-118987.rs:3:12
+   |
+LL | #![feature(specialization)]
+   |            ^^^^^^^^^^^^^^
+   |
+   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
+   = help: consider using `min_specialization` instead, which is more stable and complete
+   = note: `#[warn(incomplete_features)]` on by default
+
+warning: 1 warning emitted
+

Diff for: tests/crashes/74299.rs

@@ -1,5 +1,5 @@
 error[E0119]: conflicting implementations of trait `Overlap` for type `u32`
-  --> $DIR/specialization-default-items-drop-coherence.rs:26:1
+  --> $DIR/specialization-default-items-drop-coherence.rs:28:1
    |
 LL | impl Overlap for u32 {
    | -------------------- first implementation here

Diff for: tests/crashes/118987-2.rs renamed to tests/ui/specialization/defaultimpl/coherence-ice-issue-118987.rs

@@ -1,5 +1,5 @@
 error[E0119]: conflicting implementations of trait `Overlap` for type `u32`
-  --> $DIR/specialization-default-items-drop-coherence.rs:26:1
+  --> $DIR/specialization-default-items-drop-coherence.rs:28:1
    |
 LL | impl Overlap for u32 {
    | -------------------- first implementation here
@@ -8,7 +8,7 @@ LL | impl Overlap for <u32 as Default>::Id {
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `u32`
 
 error[E0282]: type annotations needed
-  --> $DIR/specialization-default-items-drop-coherence.rs:15:23
+  --> $DIR/specialization-default-items-drop-coherence.rs:17:23
    |
 LL |     default type Id = T;
    |                       ^ cannot infer type for associated type `<T as Default>::Id`

Diff for: tests/ui/specialization/defaultimpl/coherence-ice-issue-118987.stderr

@@ -3,6 +3,8 @@
 
 // Should fail. Default items completely drop candidates instead of ambiguity,
 // which is unsound during coherence, since coherence requires completeness.
+//
+// A regression test for #105782.
 
 #![feature(specialization)]
 #![allow(incomplete_features)]

Diff for: tests/ui/specialization/specialization-default-items-drop-coherence.current.stderr

@@ -1,9 +1,14 @@
-//@ known-bug: #124207
+// A regression test for #124207.
+//
+// This previous caused an ICE in the old solver.
 #![feature(transmutability)]
 #![feature(type_alias_impl_trait)]
 trait OpaqueTrait {}
 type OpaqueType = impl OpaqueTrait;
+//~^ ERROR unconstrained opaque type
 trait AnotherTrait {}
 impl<T: std::mem::BikeshedIntrinsicFrom<(), ()>> AnotherTrait for T {}
+//~^ ERROR type provided when a constant was expected
 impl AnotherTrait for OpaqueType {}
+//~^ ERROR conflicting implementations of trait `AnotherTrait`
 pub fn main() {}

Diff for: tests/ui/specialization/specialization-default-items-drop-coherence.next.stderr

@@ -0,0 +1,27 @@
+error: unconstrained opaque type
+  --> $DIR/opaque-type-layout-ice-issue-124207.rs:7:19
+   |
+LL | type OpaqueType = impl OpaqueTrait;
+   |                   ^^^^^^^^^^^^^^^^
+   |
+   = note: `OpaqueType` must be used in combination with a concrete type within the same module
+
+error[E0747]: type provided when a constant was expected
+  --> $DIR/opaque-type-layout-ice-issue-124207.rs:10:45
+   |
+LL | impl<T: std::mem::BikeshedIntrinsicFrom<(), ()>> AnotherTrait for T {}
+   |                                             ^^
+
+error[E0119]: conflicting implementations of trait `AnotherTrait`
+  --> $DIR/opaque-type-layout-ice-issue-124207.rs:12:1
+   |
+LL | impl<T: std::mem::BikeshedIntrinsicFrom<(), ()>> AnotherTrait for T {}
+   | ------------------------------------------------------------------- first implementation here
+LL |
+LL | impl AnotherTrait for OpaqueType {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0119, E0747.
+For more information about an error, try `rustc --explain E0119`.