Rollup merge of #154245 - ZuseZ4:autodiff-trait-support, r=JonathanBrouwer,jdonszelmann

Allow applying autodiff macros to trait functions.

It will use enzyme to generate a default derivative implementation, which can be overwritten by the user.

closes: https://github.com/rust-lang/rust/issues/153329

r? @JonathanBrouwer