Ones that stand out to me (as a wild guess):

* [Change default panic handler message format.](https://github.com/rust-lang/rust/pull/112849/)
* [Remove LLVM pointee types, supporting only opaque pointers.](https://github.com/rust-lang/rust/pull/105545/)
* [Update to LLVM 17.](https://github.com/rust-lang/rust/pull/114048/)
* [Adjust codegen change to improve LLVM codegen](https://github.com/rust-lang/rust/pull/115236)