Refactor unwind from Option to a new enum

Author: nbdd0121

src/machine.rs

@@ -868,7 +868,7 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for MiriMachine<'mir, 'tcx> {
     fn assert_panic(
         ecx: &mut MiriInterpCx<'mir, 'tcx>,
         msg: &mir::AssertMessage<'tcx>,
-        unwind: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx> {
         ecx.assert_panic(msg, unwind)
     }

src/shims/panic.rs

@@ -189,7 +189,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn assert_panic(
         &mut self,
         msg: &mir::AssertMessage<'tcx>,
-        unwind: Option<mir::BasicBlock>,
+        unwind: mir::UnwindAction,
     ) -> InterpResult<'tcx> {
         use rustc_middle::mir::AssertKind::*;
         let this = self.eval_context_mut();