allow deleting dead non-escaping closures in OSSA

Author: eeckstein

lib/SILOptimizer/Utils/InstOptUtils.cpp

@@ -1024,11 +1024,14 @@ bool swift::tryDeleteDeadClosure(SingleValueInstruction *closure,
   if (pa && pa->isOnStack()) {
     SmallVector<SILInstruction *, 8> deleteInsts;
     for (auto *use : pa->getUses()) {
-      if (isa<DeallocStackInst>(use->getUser())
-          || isa<DebugValueInst>(use->getUser()))
-        deleteInsts.push_back(use->getUser());
-      else if (!deadMarkDependenceUser(use->getUser(), deleteInsts))
+      SILInstruction *user = use->getUser();
+      if (isa<DeallocStackInst>(user)
+          || isa<DebugValueInst>(user)
+          || isa<DestroyValueInst>(user)) {
+        deleteInsts.push_back(user);
+      } else if (!deadMarkDependenceUser(user, deleteInsts)) {
         return false;
+      }
     }
     for (auto *inst : reverse(deleteInsts))
       callbacks.deleteInst(inst);