Do not attempt to autoderef `!`

This prevents error spam when attempting to look up overload traits.
Disallow dereference of `!`

Later compiler passes are not prepared to deal with deref of
`ty_bot` and will generate various ICEs, so disallow it outright for now.

Closes issue #17373
Disallow index of `!`

This avoids ICEs in later passes that cannot cope with this construct
Add regression test for issue #17373
Add test that `!` cannot be indexed
auto merge of #17408 : bkoropoff/rust/bot-ice, r=alexcrichton

- Don't attempt to autoderef `!`.  The `Deref`/`DerefMut` trait lookup would generate a bunch of unhelpful error spew.
- Don't allow explicit deref of `!`, since later passes just ICE.  This closes issue #17373 
- Don't allow explicit index of `!`, since later passes just ICE.  There does not seem to be an issue associated with this
Fix regression and overflow bug for rationals.