[libc++] Removes unneeded includes.

[Mordante]

Summary

This removes all "TODO: remove these headers" comments from our headers.

Note there seem to be more headers that can be removed, that will be
done in separate commits.

[philnik]

While you're at it you can also remove all the #include <iterator> // TODO: Remove this include.

[Mordante]

In D127592#3576162, @philnik wrote:

While you're at it you can also remove all the #include <iterator> // TODO: Remove this include.

As mentioned in the commit message I want to do more cleanups in separate commits.
The iterator is indeed on my TODO list for a separate patch.

[Mordante]

Adds missing includes in the tests.

libcxx/docs/ReleaseNotes.rst

 
 - The header ``<experimental/filesystem>`` has been removed. Instead, use
   ``<filesystem>`` header. The associated macro
   ``_LIBCPP_DEPRECATED_EXPERIMENTAL_FILESYSTEM`` has also been removed.
 
 - Some libc++ headers no longer transitively include all of:
     - ``<algorithm>``
     - ``<chrono>``
+    - ``<exception>``
     - ``<functional>``
+    - ``<new>``
+    - ``<typeinfo>``
     - ``<utility>``
 
   If, after updating libc++, you see compiler errors related to missing declarations
   in namespace ``std``, it might be because one of your source files now needs to
   include one or more of the headers listed above.
 
 - The integer distributions ``binomial_distribution``, ``discrete_distribution``,
   ``geometric_distribution``, ``negative_binomial_distribution``, ``poisson_distribution``,

libcxx/include/iterator

 #include <__memory/pointer_traits.h>
 #include <compare>
 #include <concepts> // Mandated by the Standard.
 #include <cstddef>
 #include <initializer_list>
 #include <type_traits>
 #include <version>
 
-// TODO: remove these headers
-#include <__memory/allocator_arg_t.h>
-#include <__memory/uses_allocator.h>
-#include <exception>
-#include <new>
-#include <typeinfo>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 #endif // _LIBCPP_ITERATOR

libcxx/include/optional

 #include <__utility/swap.h>
 #include <compare>
 #include <initializer_list>
 #include <new>
 #include <stdexcept>
 #include <type_traits>
 #include <version>
 
-// TODO: remove these headers
-#include <__memory/allocator_arg_t.h>
-#include <__memory/uses_allocator.h>
-#include <typeinfo>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 namespace std  // purposefully not using versioning namespace
 {
 
 class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS bad_optional_access

libcxx/include/string

 #include <iterator> // TODO: Remove this include
 #include <limits>
 #include <memory>
 #include <stdexcept>
 #include <string_view>
 #include <type_traits>
 #include <version>
 
-// TODO: remove these headers
-#include <new>
-#include <typeinfo>
-
 #ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
 #  include <cwchar>
 #endif
 
 #ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
 #  include <cstdint>
 #endif
 

libcxx/include/tuple

 #include <__utility/pair.h>
 #include <__utility/piecewise_construct.h>
 #include <__utility/swap.h>
 #include <compare>
 #include <cstddef>
 #include <type_traits>
 #include <version>
 
-// TODO: remove these headers
-#include <exception>
-#include <new>
-#include <typeinfo>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 #ifndef _LIBCPP_CXX03_LANG
 

libcxx/include/typeindex

 
 #include <__assert> // all public C++ headers provide the assertion handler
 #include <__config>
 #include <__functional/unary_function.h>
 #include <compare>
 #include <typeinfo>
 #include <version>
 
-// TODO: remove these headers
-#include <__memory/allocator_arg_t.h>
-#include <__memory/uses_allocator.h>
-#include <new>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 class _LIBCPP_TEMPLATE_VIS type_index
 {

libcxx/include/variant

 #include <exception>
 #include <initializer_list>
 #include <limits>
 #include <new>
 #include <tuple>
 #include <type_traits>
 #include <version>
 
-// TODO: remove these headers
-#include <__memory/allocator_arg_t.h>
-#include <__memory/uses_allocator.h>
-#include <typeinfo>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 namespace std { // explicitly not using versioning namespace

libcxx/include/vector

 #include <initializer_list>
 #include <iosfwd> // for forward declaration of vector
 #include <limits>
 #include <memory>
 #include <stdexcept>
 #include <type_traits>
 #include <version>
 
-// TODO: remove these headers
-#include <typeinfo>
-
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
 #endif
 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
 
 

libcxx/test/std/ranges/range.adaptors/range.join.view/types.h

 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef TEST_STD_RANGES_RANGE_ADAPTORS_RANGE_JOIN_TYPES_H
 #define TEST_STD_RANGES_RANGE_ADAPTORS_RANGE_JOIN_TYPES_H
 
 #include <concepts>
+#include <cstdint>
 #include <tuple>
 
 #include "test_macros.h"
 #include "test_iterators.h"
 
 inline int globalBuffer[4][4] = {
     {1111, 2222, 3333, 4444},
     {555, 666, 777, 888},

libcxx/test/std/utilities/utility/utility.intcmp/intcmp.in_range/in_range.pass.cpp

 // template<class R, class T>
 //   constexpr bool in_range(T t) noexcept;               // C++20
 
 #include <utility>
 #include <limits>
 #include <numeric>
 #include <tuple>
 #include <cassert>
+#include <cstdint>
 
 #include "test_macros.h"
 
 template <typename T>
 struct Tuple {
   T min;
   T max;
   T mid;