AsyncDrop implementation using shim codegen of async_drop_in_place::{closure}, scoped async drop added.

Author: azhogin

src/abi/mod.rs

@@ -441,7 +441,9 @@ pub(crate) fn codegen_terminator_call<'tcx>(
                     Err(instance) => Some(instance),
                 }
             }
-            InstanceKind::DropGlue(_, None) | ty::InstanceKind::AsyncDropGlueCtorShim(_, None) => {
+            // We don't need AsyncDropGlueCtorShim here because it is not `noop func`,
+            // it is `func returning noop future`
+            InstanceKind::DropGlue(_, None) => {
                 // empty drop glue - a nop.
                 let dest = target.expect("Non terminating drop_in_place_real???");
                 let ret_block = fx.get_block(dest);
@@ -707,9 +709,8 @@ pub(crate) fn codegen_drop<'tcx>(
     let ty = drop_place.layout().ty;
     let drop_instance = Instance::resolve_drop_in_place(fx.tcx, ty);
 
-    if let ty::InstanceKind::DropGlue(_, None) | ty::InstanceKind::AsyncDropGlueCtorShim(_, None) =
-        drop_instance.def
-    {
+    // AsyncDropGlueCtorShim can't be here
+    if let ty::InstanceKind::DropGlue(_, None) = drop_instance.def {
         // we don't actually need to drop anything
     } else {
         match ty.kind() {

src/base.rs

@@ -565,7 +565,11 @@ fn codegen_fn_body(fx: &mut FunctionCx<'_, '_, '_>, start_block: Block) {
             | TerminatorKind::CoroutineDrop => {
                 bug!("shouldn't exist at codegen {:?}", bb_data.terminator());
             }
-            TerminatorKind::Drop { place, target, unwind: _, replace: _ } => {
+            TerminatorKind::Drop { place, target, unwind: _, replace: _, drop, async_fut } => {
+                assert!(
+                    async_fut.is_none() && drop.is_none(),
+                    "Async Drop must be expanded or reset to sync before codegen"
+                );
                 let drop_place = codegen_place(fx, *place);
                 crate::abi::codegen_drop(fx, source_info, drop_place, *target);
             }