[libc++] Add deprecated attributes to many deprecated components

Summary:
These deprecation warnings are opt-in: they are only enabled when the
_LIBCXX_DEPRECATION_WARNINGS macro is defined, which is not the case
by default. Note that this is a first step in the right direction, but
I wasn't able to get an exhaustive list of all deprecated components
per standard, so there's certainly stuff that's missing. The list of
components this commit marks as deprecated is:

in C++11:
- auto_ptr, auto_ptr_ref
- binder1st, binder2nd, bind1st(), bind2nd()
- pointer_to_unary_function, pointer_to_binary_function, ptr_fun()
- mem_fun_t, mem_fun1_t, const_mem_fun_t, const_mem_fun1_t, mem_fun()
- mem_fun_ref_t, mem_fun1_ref_t, const_mem_fun_ref_t, const_mem_fun1_ref_t, mem_fun_ref()

in C++14:
- random_shuffle()

in C++17:
- unary_negate, binary_negate, not1(), not2()

<rdar://problem/18168350>

Reviewers: mclow.lists, EricWF

Subscribers: christof, dexonsmith, llvm-commits

Differential Revision: https://reviews.llvm.org/D48912

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@342843 91177308-0d34-0410-b5e6-96231b3b80d8

docs/UsingLibcxx.rst

@@ -240,6 +240,11 @@ thread safety annotations.
   purely as an extension. See :ref:`Extended Applications of [[nodiscard]] <nodiscard extension>`
   for more information.
 
+**_LIBCPP_ENABLE_DEPRECATION_WARNINGS**:
+  This macro enables warnings when using deprecated components. For example,
+  when compiling in C++11 mode, using `std::auto_ptr` with the macro defined
+  will trigger a warning saying that `std::auto_ptr` is deprecated. By default,
+  this macro is not defined.
 
 C++17 Specific Configuration Macros
 -----------------------------------