Extract handle_set_discriminant.

compiler/rustc_mir_dataflow/src/value_analysis.rs

@@ -67,8 +67,8 @@ pub trait ValueAnalysis<'tcx> {
             StatementKind::Assign(box (place, rvalue)) => {
                 self.handle_assign(*place, rvalue, state);
             }
-            StatementKind::SetDiscriminant { box ref place, .. } => {
+            StatementKind::SetDiscriminant { box place, variant_index } => {
-                state.flood_discr(place.as_ref(), self.map());
+                self.handle_set_discriminant(*place, *variant_index, state);
             }
             StatementKind::Intrinsic(box intrinsic) => {
                 self.handle_intrinsic(intrinsic, state);
@@ -94,6 +94,24 @@ pub trait ValueAnalysis<'tcx> {
         }
     }
 
+    fn handle_set_discriminant(
+        &self,
+        place: Place<'tcx>,
+        variant_index: VariantIdx,
+        state: &mut State<Self::Value>,
+    ) {
+        self.super_set_discriminant(place, variant_index, state)
+    }
+
+    fn super_set_discriminant(
+        &self,
+        place: Place<'tcx>,
+        _variant_index: VariantIdx,
+        state: &mut State<Self::Value>,
+    ) {
+        state.flood_discr(place.as_ref(), self.map());
+    }
+
     fn handle_intrinsic(
         &self,
         intrinsic: &NonDivergingIntrinsic<'tcx>,

compiler/rustc_mir_transform/src/dataflow_const_prop.rs

@@ -79,9 +79,12 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> {
         &self.map
     }
 
-    fn handle_statement(&self, statement: &Statement<'tcx>, state: &mut State<Self::Value>) {
+    fn handle_set_discriminant(
-        match statement.kind {
+        &self,
-            StatementKind::SetDiscriminant { box ref place, variant_index } => {
+        place: Place<'tcx>,
+        variant_index: VariantIdx,
+        state: &mut State<Self::Value>,
+    ) {
         state.flood_discr(place.as_ref(), &self.map);
         if self.map.find_discr(place.as_ref()).is_some() {
             let enum_ty = place.ty(self.local_decls, self.tcx).ty;
@@ -94,9 +97,6 @@ impl<'tcx> ValueAnalysis<'tcx> for ConstAnalysis<'_, 'tcx> {
             }
         }
     }
-            _ => self.super_statement(statement, state),
-        }
-    }
 
     fn handle_assign(
         &self,