Add a regression test for rust-lang#80772

Author: JohnTitor

src/test/ui/borrowck/issue-80772.rs

@@ -0,0 +1,21 @@
+// check-pass
+
+trait SomeTrait {}
+
+pub struct Exhibit {
+    constant: usize,
+    factory: fn(&usize) -> Box<dyn SomeTrait>,
+}
+
+pub const A_CONSTANT: &[Exhibit] = &[
+    Exhibit {
+        constant: 1,
+        factory: |_| unimplemented!(),
+    },
+    Exhibit {
+        constant: "Hello world".len(),
+        factory: |_| unimplemented!(),
+    },
+];
+
+fn main() {}