Internally remove workaround in Dev09_056375_locale_cleanup (#5103)

Author: CaseyCarter

tests/std/tests/Dev09_056375_locale_cleanup/test.cpp

@@ -83,9 +83,9 @@ void test_dll() {
     TheFuncProc pFunc = reinterpret_cast<TheFuncProc>(GetProcAddress(hLibrary, "DllTest"));
     assert(pFunc != nullptr);
     pFunc();
-#if defined(_DLL) || !defined(__SANITIZE_ADDRESS__) // TRANSITION, VSO-2046190
+#if defined(_MSVC_INTERNAL_TESTING) || defined(_DLL) || !defined(__SANITIZE_ADDRESS__) // TRANSITION, vs17.13p2
     FreeLibrary(hLibrary);
-#endif // defined(_DLL) || !defined(__SANITIZE_ADDRESS__)
+#endif // ^^^ no workaround ^^^
 #endif // ^^^ !defined(_M_CEE) ^^^
 }