Refactor unwind from Option to a new enum

compiler/rustc_borrowck/src/lib.rs

@@ -740,7 +740,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
                 args,
                 destination,
                 target: _,
-                cleanup: _,
+                unwind: _,
                 from_hir_call: _,
                 fn_span: _,
             } => {
@@ -750,7 +750,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
                 }
                 self.mutate_place(loc, (*destination, span), Deep, flow_state);
             }
-            TerminatorKind::Assert { cond, expected: _, msg, target: _, cleanup: _ } => {
+            TerminatorKind::Assert { cond, expected: _, msg, target: _, unwind: _ } => {
                 self.consume_operand(loc, (cond, span), flow_state);
                 use rustc_middle::mir::AssertKind;
                 if let AssertKind::BoundsCheck { len, index } = msg {
@@ -770,7 +770,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
                 options: _,
                 line_spans: _,
                 destination: _,
-                cleanup: _,
+                unwind: _,
             } => {
                 for op in operands {
                     match op {