Installed-header hygiene (BZ#20366): time.h types.

Many headers are expected to expose a subset of the type definitions
in time.h.  time.h has a whole bunch of messy logic for conditionally
defining some its types and structs, but, as best I can tell, this
has never worked 100%.  In particular, __need_timespec is ineffective
if _TIME_H has already been defined, which means that if you compile

  #include <time.h>
  #include <sched.h>

with e.g. -fsyntax-only -std=c89 -Wall -Wsystem-headers, you will get

In file included from test.c:2:0:
/usr/include/sched.h:74:57: warning: "struct timespec" declared inside
  parameter list will not be visible outside of this definition or declaration
 extern int sched_rr_get_interval (__pid_t __pid, struct timespec *__t) __THROW;
                                                         ^~~~~~~~

And if you want to _use_ sched_rr_get_interval in a TU compiled that
way, you're hosed.

This patch replaces all of that with small bits/types/TYPE.h headers
as introduced earlier.  time.h and bits/time.h are now *much* simpler,
and a lot of other headers are slightly simpler.

	* time/time.h, bits/time.h, sysdeps/unix/sysv/linux/bits/time.h:
	Remove all logic conditional on __need macros.  Move all the
	conditionally defined types to their own headers...
	* time/bits/types/clock_t.h: Define clock_t here.
	* time/bits/types/clockid_t.h: Define clockid_t here.
	* time/bits/types/struct_itimerspec.h: Define struct itimerspec here.
	* time/bits/types/struct_timespec.h: Define struct timespec here.
	* time/bits/types/struct_timeval.h: Define struct timeval here.
	* time/bits/types/struct_tm.h: Define struct tm here.
	* time/bits/types/time_t.h: Define time_t here.
	* time/bits/types/timer_t.h: Define timer_t here.
	* time/Makefile: Install the new headers.

	* bits/resource.h, io/fcntl.h, io/sys/poll.h, io/sys/stat.h
	* io/utime.h, misc/sys/select.h, posix/sched.h, posix/sys/times.h
	* posix/sys/types.h, resolv/netdb.h, rt/aio.h, rt/mqueue.h
	* signal/signal.h, pthread/semaphore.h, sysdeps/nptl/pthread.h
	* sysdeps/unix/sysv/linux/alpha/bits/resource.h
	* sysdeps/unix/sysv/linux/alpha/sys/acct.h
	* sysdeps/unix/sysv/linux/bits/resource.h
	* sysdeps/unix/sysv/linux/bits/timex.h
	* sysdeps/unix/sysv/linux/mips/bits/resource.h
	* sysdeps/unix/sysv/linux/net/ppp_defs.h
	* sysdeps/unix/sysv/linux/sparc/bits/resource.h
	* sysdeps/unix/sysv/linux/sys/acct.h
	* sysdeps/unix/sysv/linux/sys/timerfd.h
	* sysvipc/sys/msg.h, sysvipc/sys/sem.h, sysvipc/sys/shm.h
	* time/sys/time.h, time/sys/timeb.h
	Use the new bits/types headers.

	* include/time.h: Remove __need logic.
	* include/bits/time.h
	* include/bits/types/clock_t.h, include/bits/types/clockid_t.h
	* include/bits/types/time_t.h, include/bits/types/timer_t.h
	* include/bits/types/struct_itimerspec.h
	* include/bits/types/struct_timespec.h
	* include/bits/types/struct_timeval.h
	* include/bits/types/struct_tm.h:
	New wrapper headers.

8 files changed, 121 insertions, 0 deletions

diff --git a/time/bits/types/clock_t.h b/time/bits/types/clock_t.h
new file mode 100644
index 0000000000..b8cbaf2cb6
--- /dev/null
+++ b/time/bits/types/clock_t.h
@@ -0,0 +1,15 @@
+#ifndef __clock_t_defined
+#define __clock_t_defined 1
+
+#include <bits/types.h>
+
+__BEGIN_NAMESPACE_STD
+/* Returned by `clock'.  */
+typedef __clock_t clock_t;
+__END_NAMESPACE_STD
+
+#if defined __USE_XOPEN || defined __USE_POSIX
+__USING_NAMESPACE_STD(clock_t)
+#endif
+
+#endif
diff --git a/time/bits/types/clockid_t.h b/time/bits/types/clockid_t.h
new file mode 100644
index 0000000000..b17c7da853
--- /dev/null
+++ b/time/bits/types/clockid_t.h
@@ -0,0 +1,9 @@
+#ifndef __clockid_t_defined
+#define __clockid_t_defined 1
+
+#include <bits/types.h>
+
+/* Clock ID used in clock and timer functions.  */
+typedef __clockid_t clockid_t;
+
+#endif
diff --git a/time/bits/types/struct_itimerspec.h b/time/bits/types/struct_itimerspec.h
new file mode 100644
index 0000000000..17cc1ac86d
--- /dev/null
+++ b/time/bits/types/struct_itimerspec.h
@@ -0,0 +1,14 @@
+#ifndef __itimerspec_defined
+#define __itimerspec_defined 1
+
+#include <bits/types.h>
+#include <bits/types/struct_timespec.h>
+
+/* POSIX.1b structure for timer start values and intervals.  */
+struct itimerspec
+  {
+    struct timespec it_interval;
+    struct timespec it_value;
+  };
+
+#endif
diff --git a/time/bits/types/struct_timespec.h b/time/bits/types/struct_timespec.h
new file mode 100644
index 0000000000..644db9fdb6
--- /dev/null
+++ b/time/bits/types/struct_timespec.h
@@ -0,0 +1,14 @@
+#ifndef __timespec_defined
+#define __timespec_defined 1
+
+#include <bits/types.h>
+
+/* POSIX.1b structure for a time value.  This is like a `struct timeval' but
+   has nanoseconds instead of microseconds.  */
+struct timespec
+{
+  __time_t tv_sec;		/* Seconds.  */
+  __syscall_slong_t tv_nsec;	/* Nanoseconds.  */
+};
+
+#endif
diff --git a/time/bits/types/struct_timeval.h b/time/bits/types/struct_timeval.h
new file mode 100644
index 0000000000..70394ce886
--- /dev/null
+++ b/time/bits/types/struct_timeval.h
@@ -0,0 +1,13 @@
+#ifndef __timeval_defined
+#define __timeval_defined 1
+
+#include <bits/types.h>
+
+/* A time value that is accurate to the nearest
+   microsecond but also has a range of years.  */
+struct timeval
+{
+  __time_t tv_sec;		/* Seconds.  */
+  __suseconds_t tv_usec;	/* Microseconds.  */
+};
+#endif
diff --git a/time/bits/types/struct_tm.h b/time/bits/types/struct_tm.h
new file mode 100644
index 0000000000..8f5af16715
--- /dev/null
+++ b/time/bits/types/struct_tm.h
@@ -0,0 +1,33 @@
+#ifndef __struct_tm_defined
+#define __struct_tm_defined 1
+
+#include <bits/types.h>
+
+/* ISO C `broken-down time' structure.  */
+__BEGIN_NAMESPACE_STD
+struct tm
+{
+  int tm_sec;			/* Seconds.	[0-60] (1 leap second) */
+  int tm_min;			/* Minutes.	[0-59] */
+  int tm_hour;			/* Hours.	[0-23] */
+  int tm_mday;			/* Day.		[1-31] */
+  int tm_mon;			/* Month.	[0-11] */
+  int tm_year;			/* Year	- 1900.  */
+  int tm_wday;			/* Day of week.	[0-6] */
+  int tm_yday;			/* Days in year.[0-365]	*/
+  int tm_isdst;			/* DST.		[-1/0/1]*/
+
+# ifdef	__USE_MISC
+  long int tm_gmtoff;		/* Seconds east of UTC.  */
+  const char *tm_zone;		/* Timezone abbreviation.  */
+# else
+  long int __tm_gmtoff;		/* Seconds east of UTC.  */
+  const char *__tm_zone;	/* Timezone abbreviation.  */
+# endif
+};
+__END_NAMESPACE_STD
+#if defined __USE_XOPEN || defined __USE_POSIX
+__USING_NAMESPACE_STD(tm)
+#endif
+
+#endif
diff --git a/time/bits/types/time_t.h b/time/bits/types/time_t.h
new file mode 100644
index 0000000000..16e5269184
--- /dev/null
+++ b/time/bits/types/time_t.h
@@ -0,0 +1,14 @@
+#ifndef __time_t_defined
+#define __time_t_defined 1
+
+#include <bits/types.h>
+
+__BEGIN_NAMESPACE_STD
+/* Returned by `time'.  */
+typedef __time_t time_t;
+__END_NAMESPACE_STD
+#ifdef __USE_POSIX
+__USING_NAMESPACE_STD(time_t)
+#endif
+
+#endif
diff --git a/time/bits/types/timer_t.h b/time/bits/types/timer_t.h
new file mode 100644
index 0000000000..d71a4130e2
--- /dev/null
+++ b/time/bits/types/timer_t.h
@@ -0,0 +1,9 @@
+#ifndef __timer_t_defined
+#define __timer_t_defined 1
+
+#include <bits/types.h>
+
+/* Timer ID returned by `timer_create'.  */
+typedef __timer_t timer_t;
+
+#endif