message: `let`-bind `exp_abi` of `"exit" | "ExitProcess"`
diff: @@ -238,7 +238,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
  | "exit"
  | "ExitProcess"
  => {
  - let &[ref code] = this.check_shim(abi, if link_name == "exit" { Abi::C { unwind: false } } else { Abi::System { unwind: false } }, link_name_sym, args)?;
  + let exp_abi = if link_name == "exit" {
  + Abi::C { unwind: false }
  + } else {
  + Abi::System { unwind: false }
  + };
  + let &[ref code] = this.check_shim(abi, exp_abi, link_name_sym, args)?;
  // it's really u32 for ExitProcess, but we have to put it into the `Exit` variant anyway
  let code = this.read_scalar(code)?.to_i32()?;
  throw_machine_stop!(TerminationInfo::Exit(code.into()));
  