Mention rust-lang#79078 on compatibility notes of 1.52

Author: JohnTitor

RELEASES.md

@@ -320,6 +320,7 @@ Compatibility Notes
 - [Rustc now catches more cases of `pub_use_of_private_extern_crate`][80763]
 - [Changes in how proc macros handle whitespace may lead to panics when used
   with older `proc-macro-hack` versions. A `cargo update` should be sufficient to fix this in all cases.][84136]
+- [Turn `#[derive]` into a regular macro attribute][79078]
 
 [84136]: https://github.com/rust-lang/rust/issues/84136
 [80763]: https://github.com/rust-lang/rust/pull/80763
@@ -346,6 +347,7 @@ Compatibility Notes
 [78429]: https://github.com/rust-lang/rust/pull/78429
 [82733]: https://github.com/rust-lang/rust/pull/82733
 [82594]: https://github.com/rust-lang/rust/pull/82594
+[79078]: https://github.com/rust-lang/rust/pull/79078
 [cargo/9181]: https://github.com/rust-lang/cargo/pull/9181
 [`char::MAX`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.MAX
 [`char::REPLACEMENT_CHARACTER`]: https://doc.rust-lang.org/std/primitive.char.html#associatedconstant.REPLACEMENT_CHARACTER