[libc++] Workaround unused variable warning in test
This only showed up in C++11/C++14 where the static_assert below was
ifdef'd out, and the variable was indeed unused.
diff --git a/libcxx/test/std/atomics/types.pass.cpp b/libcxx/test/std/atomics/types.pass.cpp
index ba6d694..f891f90 100644
--- a/libcxx/test/std/atomics/types.pass.cpp
+++ b/libcxx/test/std/atomics/types.pass.cpp
@@ -34,7 +34,7 @@
void
test_atomic()
{
- A a;
+ A a; (void)a;
#if TEST_STD_VER >= 17
static_assert((std::is_same<typename A::value_type, decltype(a.load())>::value), "");
#endif
