Document `panic!` for Iterator::last (Repeat)

[tdelmas]

Location (URL)

https://doc.rust-lang.org/nightly/std/iter/trait.Iterator.html#method.last
https://doc.rust-lang.org/nightly/std/iter/struct.Repeat.html#method.last

Summary

https://doc.rust-lang.org/nightly/src/core/iter/sources/repeat.rs.html#105

This panic! is not documented. Neither in Iterator::last nor in repeat.

#146410