translate bid into nop for stable mir

Author: dingxiangfei2009

compiler/rustc_smir/src/rustc_smir/convert/mir.rs

@@ -151,11 +151,9 @@ impl<'tcx> Stable<'tcx> for mir::StatementKind<'tcx> {
             mir::StatementKind::ConstEvalCounter => {
                 stable_mir::mir::StatementKind::ConstEvalCounter
             }
-            mir::StatementKind::BackwardIncompatibleDropHint { place, reason } => {
-                stable_mir::mir::StatementKind::BackwardIncompatibleDropHint {
-                    place: place.stable(tables),
-                    reason: reason.stable(tables),
-                }
+            // BackwardIncompatibleDropHint has no semantics, so it is translated to Nop.
+            mir::StatementKind::BackwardIncompatibleDropHint { .. } => {
+                stable_mir::mir::StatementKind::Nop
             }
             mir::StatementKind::Nop => stable_mir::mir::StatementKind::Nop,
         }
@@ -451,18 +449,6 @@ impl<'tcx> Stable<'tcx> for mir::NonDivergingIntrinsic<'tcx> {
     }
 }
 
-impl<'tcx> Stable<'tcx> for mir::BackwardIncompatibleDropReason {
-    type T = stable_mir::mir::BackwardIncompatibleDropReason;
-
-    fn stable(&self, _tables: &mut Tables<'_>) -> Self::T {
-        match self {
-            mir::BackwardIncompatibleDropReason::Edition2024 => {
-                stable_mir::mir::BackwardIncompatibleDropReason::Edition2024
-            }
-        }
-    }
-}
-
 impl<'tcx> Stable<'tcx> for mir::AssertMessage<'tcx> {
     type T = stable_mir::mir::AssertMessage;
     fn stable(&self, tables: &mut Tables<'_>) -> Self::T {

compiler/stable_mir/src/mir/body.rs

@@ -448,15 +448,9 @@ pub enum StatementKind {
     Coverage(Coverage),
     Intrinsic(NonDivergingIntrinsic),
     ConstEvalCounter,
-    BackwardIncompatibleDropHint { place: Place, reason: BackwardIncompatibleDropReason },
     Nop,
 }
 
-#[derive(Clone, Debug, Eq, PartialEq, Serialize)]
-pub enum BackwardIncompatibleDropReason {
-    Edition2024,
-}
-
 #[derive(Clone, Debug, Eq, PartialEq, Serialize)]
 pub enum Rvalue {
     /// Creates a pointer with the indicated mutability to the place.

compiler/stable_mir/src/mir/visit.rs

@@ -224,9 +224,7 @@ pub trait MirVisitor {
                     self.visit_operand(count, location);
                 }
             },
-            StatementKind::BackwardIncompatibleDropHint { .. }
-            | StatementKind::ConstEvalCounter
-            | StatementKind::Nop => {}
+            StatementKind::ConstEvalCounter | StatementKind::Nop => {}
         }
     }