[cxx-interop] attempt to fix windows unique ptr test

Author: hyp

test/Interop/Cxx/stdlib/Inputs/std-unique-ptr.h

@@ -17,6 +17,8 @@ std::unique_ptr<int[]> makeArray() {
 
 static bool dtorCalled = false;
 struct HasDtor {
+  inline HasDtor() {}
+  inline HasDtor(const HasDtor &other);
   ~HasDtor() {
     dtorCalled = true;
   }