Exclude a C++17 test (currently in PR #3294) on macOS since it suffers from...

Exclude a C++17 test (currently in PR #3294) on macOS since it suffers from the same incompatibility issues as the other C++17 tests.

tests/macos_cpp_bugs.txt

@@ -7,7 +7,8 @@ cpp_classes_def
 cpp_smart_ptr
 cpp_stl_conversion
 cpp_stl_function
+cpp_stl_optional
 cpp_stl_algo_comparison_ops
 cpp_stl_algo_permutation_ops
 cpp_stl_algo_sorted_ranges_set_ops
-cpp_stl_algo_sorted_ranges_other_ops
\ No newline at end of file
+cpp_stl_algo_sorted_ranges_other_ops