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()

test/std/utilities/function.objects/bitwise.operations/bit_xor.pass.cpp

@@ -17,6 +17,7 @@
 
 int main()
 {
+    {
     typedef std::bit_xor<int> F;
     const F f = F();
     static_assert((std::is_same<int, F::first_argument_type>::value), "" );
@@ -27,9 +28,11 @@ int main()
     assert(f(0x58D3, 0xEA95) == 0xB246);
     assert(f(0x58D3, 0) == 0x58D3);
     assert(f(0xFFFF, 0x58D3) == 0xA72C);
+    }
 #if _LIBCPP_STD_VER > 11
+    {
     typedef std::bit_xor<> F2;
-    const F2 f2 = F2();
+    const F2 f = F2();
     assert(f(0xEA95, 0xEA95) == 0);
     assert(f(0xEA95L, 0xEA95) == 0);
     assert(f(0xEA95, 0xEA95L) == 0);
@@ -55,5 +58,6 @@ int main()
 
     constexpr int bar = std::bit_xor<> () (0x58D3L, 0xEA95);
     static_assert ( bar == 0xB246, "" );
+    }
 #endif
 }