libstdc++: Move C++14 <chrono> components to new <bits/chrono.h> header

This moves the "classic" contents of <chrono> to a new header, so that
<future>, <thread> etc. can get use durations and clocks without
calendar types, time zones, and chrono I/O.

libstdc++-v3/ChangeLog:

	* include/Makefile.am: Add new header.
	* include/Makefile.in: Regenerate.
	* include/std/chrono (duration, time_point, system_clock)
	(steady_clock, high_resolution_clock, chrono_literals, sys_time)
	(file_clock, file_time): Move to ...
	* include/bits/chrono.h: New file.
	* include/bits/atomic_futex.h: Include new header instead of
	<chrono>.
	* include/bits/atomic_timed_wait.h: Likewise.
	* include/bits/fs_fwd.h: Likewise.
	* include/bits/semaphore_base.h: Likewise.
	* include/bits/this_thread_sleep.h: Likewise.
	* include/bits/unique_lock.h: Likewise.
	* include/experimental/bits/fs_fwd.h: Likewise.
	* include/experimental/chrono: Likewise.
	* include/experimental/io_context: Likewise.
	* include/experimental/netfwd: Likewise.
	* include/experimental/timer: Likewise.
	* include/std/condition_variable: Likewise.
	* include/std/mutex: Likewise.
	* include/std/shared_mutex: Likewise.

libstdc++-v3/include/Makefile.am

@@ -117,6 +117,7 @@ bits_headers = \
 	${bits_srcdir}/c++0x_warning.h \
 	${bits_srcdir}/char_traits.h \
 	${bits_srcdir}/charconv.h \
+	${bits_srcdir}/chrono.h \
 	${bits_srcdir}/codecvt.h \
 	${bits_srcdir}/concept_check.h \
 	${bits_srcdir}/cow_string.h \

libstdc++-v3/include/Makefile.in

@@ -467,6 +467,7 @@ bits_headers = \
 	${bits_srcdir}/c++0x_warning.h \
 	${bits_srcdir}/char_traits.h \
 	${bits_srcdir}/charconv.h \
+	${bits_srcdir}/chrono.h \
 	${bits_srcdir}/codecvt.h \
 	${bits_srcdir}/concept_check.h \
 	${bits_srcdir}/cow_string.h \

libstdc++-v3/include/bits/atomic_futex.h

@@ -32,13 +32,12 @@
 
 #pragma GCC system_header
 
-#include <bits/c++config.h>
 #include <atomic>
-#include <chrono>
 #if ! (defined(_GLIBCXX_HAVE_LINUX_FUTEX) && ATOMIC_INT_LOCK_FREE > 1)
 #include <mutex>
 #include <condition_variable>
 #endif
+#include <bits/chrono.h>
 
 #ifndef _GLIBCXX_ALWAYS_INLINE
 #define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__))

libstdc++-v3/include/bits/atomic_timed_wait.h

@@ -37,8 +37,7 @@
 #if __cpp_lib_atomic_wait
 #include <bits/functional_hash.h>
 #include <bits/this_thread_sleep.h>
-
-#include <chrono>
+#include <bits/chrono.h>
 
 #ifdef _GLIBCXX_HAVE_LINUX_FUTEX
 #include <exception> // std::terminate

libstdc++-v3/include/bits/fs_fwd.h

@@ -34,7 +34,7 @@
 
 #include <system_error>
 #include <cstdint>
-#include <chrono>
+#include <bits/chrono.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {

libstdc++-v3/include/bits/semaphore_base.h

@@ -33,6 +33,7 @@
 #pragma GCC system_header
 
 #include <bits/atomic_base.h>
+#include <bits/chrono.h>
 #if __cpp_lib_atomic_wait
 #include <bits/atomic_timed_wait.h>
 #include <ext/numeric_traits.h>
@@ -45,9 +46,6 @@
 # include <semaphore.h>	// sem_t, sem_init, sem_wait, sem_post etc.
 #endif
 
-#include <chrono>
-#include <type_traits>
-
 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION

libstdc++-v3/include/bits/this_thread_sleep.h

@@ -33,9 +33,7 @@
 #pragma GCC system_header
 
 #if __cplusplus >= 201103L
-#include <bits/c++config.h>
-
-#include <chrono> // std::chrono::*
+#include <bits/chrono.h> // std::chrono::*
 
 #ifdef _GLIBCXX_USE_NANOSLEEP
 # include <cerrno>  // errno, EINTR

libstdc++-v3/include/bits/unique_lock.h

@@ -36,7 +36,7 @@
 # include <bits/c++0x_warning.h>
 #else
 
-#include <chrono>
+#include <bits/chrono.h>
 #include <bits/move.h> // for std::swap
 #include <bits/std_mutex.h> // for std::defer_lock_t
 

libstdc++-v3/include/experimental/bits/fs_fwd.h

@@ -36,7 +36,7 @@
 
 #include <system_error>
 #include <cstdint>
-#include <chrono>
+#include <bits/chrono.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {

libstdc++-v3/include/experimental/chrono

@@ -38,7 +38,7 @@
 
 #if __cplusplus >= 201402L
 
-#include <chrono>
+#include <bits/chrono.h> // Only the C++14 parts of <chrono>
 #include <experimental/bits/lfts_config.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)

libstdc++-v3/include/experimental/io_context

@@ -35,7 +35,6 @@
 #if __cplusplus >= 201402L
 
 #include <atomic>
-#include <chrono>
 #include <forward_list>
 #include <functional>
 #include <system_error>
@@ -43,6 +42,7 @@
 #include <vector>
 #include <experimental/netfwd>
 #include <experimental/executor>
+#include <bits/chrono.h>
 #if _GLIBCXX_HAVE_UNISTD_H
 # include <unistd.h>
 #endif

libstdc++-v3/include/experimental/netfwd

@@ -37,7 +37,7 @@
 // #define __cpp_lib_experimental_net 201803
 // #define __cpp_lib_experimental_net_extensible 201803
 
-#include <chrono>
+#include <bits/chrono.h>
 
 namespace std _GLIBCXX_VISIBILITY(default)
 {

libstdc++-v3/include/experimental/timer

@@ -34,7 +34,7 @@
 
 #if __cplusplus >= 201402L
 
-#include <chrono>
+#include <bits/chrono.h>
 #include <system_error>
 #include <thread>
 #include <experimental/netfwd>

libstdc++-v3/include/std/condition_variable

@@ -35,8 +35,7 @@
 # include <bits/c++0x_warning.h>
 #else
 
-#include <chrono>
-
+#include <bits/chrono.h>
 #include <bits/std_mutex.h>
 #include <bits/unique_lock.h>
 #include <bits/alloc_traits.h>

libstdc++-v3/include/std/mutex

@@ -36,10 +36,10 @@
 #else
 
 #include <tuple>
-#include <chrono>
 #include <exception>
 #include <type_traits>
 #include <system_error>
+#include <bits/chrono.h>
 #include <bits/std_mutex.h>
 #include <bits/unique_lock.h>
 #if ! _GTHREAD_USE_MUTEX_TIMEDLOCK

libstdc++-v3/include/std/shared_mutex

@@ -33,7 +33,7 @@
 
 #if __cplusplus >= 201402L
 
-#include <chrono>
+#include <bits/chrono.h>
 #include <bits/functexcept.h>
 #include <bits/move.h>        // move, __exchange
 #include <bits/std_mutex.h>   // defer_lock_t