[MS Compatibility] Handle cleanups we create for a ctor closure

This fixes PR23801.

llvm-svn: 239503
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index c80ef2d..7ed9bfc 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -9494,6 +9494,7 @@
 
       Expr *DefaultArg = S.BuildCXXDefaultArgExpr(Class->getLocation(), CD,
                                                   CD->getParamDecl(I)).get();
+      S.DiscardCleanupsInEvaluationContext();
       S.Context.addDefaultArgExprForConstructor(CD, I, DefaultArg);
     }
   }