core::panicking module docs are outdated

[RalfJung]

The module docs at the top of https://github.com/rust-lang/rust/blob/e41ced3f8d8e2f3f377ef931458e612d5f3d1f3f/src/libcore/panicking.rs seem outdated: they mention fn panic_impl(fmt: fmt::Arguments, file_line_col: &(&'static str, u32, u32)) -> ! as the signature for the panic_impl, but the actual signature at the bottom of the same file is fn panic_impl(pi: &PanicInfo<'_>) -> !.

The comment also says that it does not allow failing with a Box<Any> value, but PanicInfo contains something very similar, a &'a (dyn Any + Send).

I would send a PR adjusting the signature, but the second makes be belief someone with some actual knowledge of our panicking infrastructure should look at this.

Cc @alexcrichton

[alexcrichton]

Yes the signature has bitrotted over time and just needs an update, the bit about Box is libcore-specific and still accurate though.

[Mark-Simulacrum]

I think #66694 updated the comments as needed and seems consistent with the state of the world today, so closing (but feel free to reopen of course if I'm wrong!)