cmake DEAL_II_HAVE_CXX11_FUNCTIONAL_LLVMBUG20084_OK examples

dealii/dealii cmake/checks/check_01_cxx_features.cmake :320 

CHECK_CXX_SOURCE_COMPILES(
    "
    #include <functional>
    struct A { void foo() const {} };
    int main() { A a; std::bind(&A::foo,a)(); return 0; }
    "
    DEAL_II_HAVE_CXX11_FUNCTIONAL_LLVMBUG20084_OK)