Get tests running with warnings. Fix warnings in headers and tests

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@228344 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/utilities/function.objects/bind/func.bind/func.bind.bind/invoke_lvalue.pass.cpp

@@ -276,6 +276,7 @@ test3()
     const auto f = bind(&TFENode::foo, _1, 0UL);
     const TFENode n = TFENode{};
     bool b = f(n);
+    assert(b);
 }
 
 int main()

test/std/utilities/function.objects/bind/func.bind/func.bind.place/placeholders.pass.cpp

@@ -12,13 +12,20 @@
 // placeholders
 
 #include <functional>
+#include <type_traits>
 
 template <class T>
 void
 test(const T& t)
 {
+    // Test default constructible.
     T t2;
+    ((void)t2);
+    // Test copy constructible.
     T t3 = t;
+    ((void)t3);
+    static_assert(std::is_nothrow_copy_constructible<T>::value, "");
+    static_assert(std::is_nothrow_move_constructible<T>::value, "");
 }
 
 int main()