message: Update panic runtime comment
diff: @@ -132,7 +132,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  match link_name {
  // Note that this matches calls to the *foreign* item `__rust_start_panic* -
  // that is, calls to `extern "Rust" { fn __rust_start_panic(...) }`.
  - // We forward this to the underlying *implementation* in "libpanic_unwind".
  + // We forward this to the underlying *implementation* in the panic runtime crate.
  + // Normally, this will be either `libpanic_unwind` or `libpanic_abort`, but it could
  + // also be a custom user-provided implementation via `#![feature(panic_runtime)]`
  "__rust_start_panic" => {
  let panic_runtime = tcx.crate_name(tcx.injected_panic_runtime().expect("No panic runtime found!"));
  let start_panic_instance = this.resolve_path(&[&*panic_runtime.as_str(), "__rust_start_panic"])?;
  