Rollup merge of #161199 - lsunsi:issue155802, r=ShoyuVanilla

Add regression test for non lifetime binders

Closes #155802.

I was able to reduce the code to generate the ICE even without the `#![feature(non_lifetime_binders)]` (using treereduce).
I left it there as is on the issue because I thought it might change the example too much from it's origin.

Question for reviewer, is it better to have a really really minimal example in this case? I could update the PR if it's needed.

Author: jhpratt

tests/ui/traits/non_lifetime_binders/expected-region-found-kind.rs

@@ -0,0 +1,21 @@
+//! Regression test for <https://github.com/rust-lang/rust/issues/155802>.
+//@ check-fail
+
+#![feature(non_lifetime_binders)]
+trait E<'e> {
+    type As;
+}
+
+trait F<'a>: for<F> E<'a> + for<'e> E<'e> {}
+//~^ ERROR type annotations needed: cannot satisfy `Self: E<'a>` [E0283]
+
+struct G<'a, T>
+where
+    T: F<'a, As: E<'a>>,
+    //~^ ERROR type annotations needed: cannot satisfy `T: E<'a>` [E0283]
+    //~| ERROR ambiguous associated type `As` in bounds of `F` [E0221]
+{
+    x: &'a T,
+}
+
+fn main() {}

tests/ui/traits/non_lifetime_binders/expected-region-found-kind.stderr

@@ -0,0 +1,45 @@
+error[E0283]: type annotations needed: cannot satisfy `Self: E<'a>`
+  --> $DIR/expected-region-found-kind.rs:9:14
+   |
+LL | trait F<'a>: for<F> E<'a> + for<'e> E<'e> {}
+   |              ^^^^^^^^^^^^
+   |
+note: multiple `impl`s or `where` clauses satisfying `Self: E<'a>` found
+  --> $DIR/expected-region-found-kind.rs:9:14
+   |
+LL | trait F<'a>: for<F> E<'a> + for<'e> E<'e> {}
+   |              ^^^^^^^^^^^^   ^^^^^^^^^^^^^
+
+error[E0221]: ambiguous associated type `As` in bounds of `F`
+  --> $DIR/expected-region-found-kind.rs:14:14
+   |
+LL |     type As;
+   |     -------
+   |     |
+   |     ambiguous `As` from `for<'e> E<'e>`
+   |     ambiguous `As` from `E<'a>`
+...
+LL |     T: F<'a, As: E<'a>>,
+   |              ^^^^^^^^^ ambiguous associated type `As`
+
+error[E0283]: type annotations needed: cannot satisfy `T: E<'a>`
+  --> $DIR/expected-region-found-kind.rs:14:8
+   |
+LL |     T: F<'a, As: E<'a>>,
+   |        ^^^^^^^^^^^^^^^^
+   |
+note: multiple `impl`s or `where` clauses satisfying `T: E<'a>` found
+  --> $DIR/expected-region-found-kind.rs:14:8
+   |
+LL |     T: F<'a, As: E<'a>>,
+   |        ^^^^^^^^^^^^^^^^
+note: required by a bound in `F`
+  --> $DIR/expected-region-found-kind.rs:9:14
+   |
+LL | trait F<'a>: for<F> E<'a> + for<'e> E<'e> {}
+   |              ^^^^^^^^^^^^ required by this bound in `F`
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0221, E0283.
+For more information about an error, try `rustc --explain E0221`.