Fix sys/time.h timespec namespace (bug 20041).
For UNIX98 and older standards, sys/time.h should not define struct
timespec, but does so via the inclusion of sys/select.h (which is a
new header in the 2001 edition of POSIX, and defines struct timespec
because of the declaration of pselect, a new function in the 2001
edition of POSIX). In turn, this affects some other headers that
themselves include sys/time.h.
This patch fixes this by conditioning the __need_timespec definition
in sys/select.h on __USE_XOPEN2K, the same condition used there for
the declaration of pselect (this has no effect on direct uses of
sys/select.h with feature test macros for any standard that includes
that header, since such standards result in __USE_XOPEN2K being
defined).
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
[BZ #20041]
* misc/sys/select.h (__need_timespec): Only define if
[__USE_XOPEN2K].
* conform/Makefile (test-xfail-XPG4/sys/time.h/conform): Remove
variable.
(test-xfail-XPG4/utmpx.h/conform): Likewise.
(test-xfail-UNIX98/sys/time.h/conform): Likewise.
(test-xfail-UNIX98/utmpx.h/conform): Likewise.