[libc++] Include headers in <thread> conditionally (#116539)

Author: philnik777

libcxx/include/thread

@@ -90,11 +90,17 @@ void sleep_for(const chrono::duration<Rep, Period>& rel_time);
 
 #if _LIBCPP_HAS_THREADS
 
-#  include <__thread/formatter.h>
-#  include <__thread/jthread.h>
-#  include <__thread/support.h>
 #  include <__thread/this_thread.h>
 #  include <__thread/thread.h>
+
+#  if _LIBCPP_STD_VER >= 20
+#    include <__thread/jthread.h>
+#  endif
+
+#  if _LIBCPP_STD_VER >= 23
+#    include <__thread/formatter.h>
+#  endif
+
 #  include <version>
 
 // standard-mandated includes
@@ -108,13 +114,6 @@ void sleep_for(const chrono::duration<Rep, Period>& rel_time);
 
 #endif // _LIBCPP_HAS_THREADS
 
-#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES)
-#  include <cstddef>
-#  include <ctime>
-#  include <iosfwd>
-#  include <ratio>
-#endif
-
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 17
 #  include <chrono>
 #endif

libcxx/test/benchmarks/atomic_wait.bench.cpp

@@ -9,6 +9,7 @@
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 #include <atomic>
+#include <cstdint>
 #include <numeric>
 #include <stop_token>
 #include <thread>

libcxx/test/benchmarks/atomic_wait_vs_mutex_lock.bench.cpp

@@ -9,8 +9,8 @@
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
 #include <atomic>
+#include <cstdint>
 #include <mutex>
-#include <numeric>
 #include <stop_token>
 #include <thread>
 

libcxx/test/benchmarks/stop_token.bench.cpp

@@ -8,7 +8,7 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 
-#include <numeric>
+#include <cstdint>
 #include <optional>
 #include <stop_token>
 #include <thread>

libcxx/test/libcxx/thread/thread.stoptoken/atomic_unique_lock.pass.cpp

@@ -15,6 +15,7 @@
 #include <atomic>
 #include <cassert>
 #include <chrono>
+#include <cstdint>
 #include <thread>
 
 #include "make_test_thread.h"

libcxx/test/std/thread/thread.semaphore/max.pass.cpp

@@ -11,10 +11,8 @@
 
 // <semaphore>
 
+#include <cstddef>
 #include <semaphore>
-#include <thread>
-
-#include "test_macros.h"
 
 int main(int, char**)
 {