fixup of codegen/ref-dyn-trait-in-structs-and-enums.rs

Author: spencer3035

tests/ui/codegen/ref-dyn-trait-in-structs-and-enums.rs

@@ -1,9 +1,9 @@
-//! Ensure code generation when using polymorphic references does not trigger an LLVM assertion
+//! Regression test for an LLVM assertion that used to be hit when:
 //!
-//! This is checked in three methods:
-//! - `&dyn MyTrait` references in an enum variant wrapped in an unnamed field of a struct
-//! - `&dyn MyTrait` references in an `Option` for a named field in a struct
-//! - `&dyn MyTrait` references in an `Option` for an unnamed field in a struct
+//! - There's a generic enum contained within a tuple struct
+//! - When the tuple struct is parameterized by some lifetime `'a`
+//! - The enum is concretized with its type argument being a reference to a trait object (of
+//!   lifetime `'a`)
 //!
 //! Issue: <https://github.com/rust-lang/rust/issues/9719>