* init.c: Make it compile with older kernel headers.

* init.c: Make it compile with older kernel headers.

	* tst-initializers1.c: Show through exit code which test failed.

	* pthread_rwlock_init.c: Also initialize __shared field.
	* sysdeps/unix/sysv/linux/i386/bits/pthreadtypes.h: Split __flags
	element in rwlock structure into four byte elements.  One of them is
	the new __shared element.
	* sysdeps/unix/sysv/linux/x86_64/bits/pthreadtypes.h [__WORDSIZE=32]:
	Likewise.
	[__WORDSIZE=64]: Renamed __pad1 element int rwlock structire to
	__shared, adjust names of other padding elements.
	* sysdeps/unix/sysv/linux/powerpc/bits/pthreadtypes.h: Likewise.
	* sysdeps/pthread/pthread.h: Adjust rwlock initializers.
	* sysdeps/unix/sysv/linux/lowlevelrwlock.sym: Add PSHARED.
	* sysdeps/unix/sysv/linux/powerpc/lowlevellock.h: Define
	FUTEX_PRIVATE_FLAG.
	* sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_rdlock.S: Change main
	futex to use private operations if possible.
	* sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_timedrdlock.S:
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_timedwrlock.S:
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_unlock.S: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/pthread_rwlock_wrlock.S: Likewise.