Auto merge of #112599 - saethlin:cleaner-panics, r=thomcc

Launch a non-unwinding panic for misaligned pointer deref

This panic already never unwinds, but that's only because it always hits the unwind guard that's created by our `UnwindAction::Terminate`. Hitting the unwind guard generates a huge double-panic backtrace. Now we generate a normal-looking panic message when this check is hit.

r? `@thomcc`

Author: bors