Auto merge of #13763 - rami3l:fix/gen-partial-eq-generic, r=Veykril
fix: add generic `TypeBoundList` in generated derivable impl
Potentially fixes #13727.
Continuing with the work in #13732, this fix tries to add correct type bounds in the generated `impl` block:
```diff
enum Either<T, U> {
Left(T),
Right(U),
}
- impl<T, U> PartialEq for Either<T, U> {
+ impl<T: PartialEq, U: PartialEq> PartialEq for Either<T, U> {
fn eq(&self, other: &Self) -> bool {
match (self, other) {
(Self::Left(l0), Self::Left(r0)) => l0 == r0,
(Self::Right(l0), Self::Right(r0)) => l0 == r0,
_ => false,
}
}
}
```