add test for ice "cannot relate region: LUB(ReErased, ReError)"

tests/ui/inference/ice-cannot-relate-region-109178.rs

@@ -0,0 +1,14 @@
+// test for ice #109178  cannot relate region: LUB(ReErased, ReError)
+
+#![allow(incomplete_features)]
+#![crate_type = "lib"]
+#![feature(adt_const_params, generic_const_exprs)]
+
+struct Changes<const CHANGES: &[&'static str]>
+//~^ ERROR `&` without an explicit lifetime name cannot be used here
+where
+    [(); CHANGES.len()]:, {}
+
+impl<const CHANGES: &[&str]> Changes<CHANGES> where [(); CHANGES.len()]: {}
+//~^ ERROR `&` without an explicit lifetime name cannot be used here
+//~^^ ERROR `&` without an explicit lifetime name cannot be used here

tests/ui/inference/ice-cannot-relate-region-109178.stderr

@@ -0,0 +1,21 @@
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/ice-cannot-relate-region-109178.rs:7:31
+   |
+LL | struct Changes<const CHANGES: &[&'static str]>
+   |                               ^ explicit lifetime name needed here
+
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/ice-cannot-relate-region-109178.rs:12:21
+   |
+LL | impl<const CHANGES: &[&str]> Changes<CHANGES> where [(); CHANGES.len()]: {}
+   |                     ^ explicit lifetime name needed here
+
+error[E0637]: `&` without an explicit lifetime name cannot be used here
+  --> $DIR/ice-cannot-relate-region-109178.rs:12:23
+   |
+LL | impl<const CHANGES: &[&str]> Changes<CHANGES> where [(); CHANGES.len()]: {}
+   |                       ^ explicit lifetime name needed here
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0637`.