Add tests for namespace for static linking.

Add tests for namespace for static linking.

One thing we currently try to ensure manually is that glibc is
namespace-clean for static linking; that is, if you only use features
from a particular standard (including the set of features exposed by
headers given feature test macros such as _DEFAULT_SOURCE that don't
correspond to any written standard), the library objects brought in by
the static linker will not define or use (strong) names that are
reserved to the user in that standard.

This patch implements automatic tests for this, using the same set of
standards as for the header conformance tests (it would, however, be
easy to add more standards for this testing, without them needing to
have the definitions of expected header contents for the header
tests).  The tests are based on the functions declared in each header,
as extracted using GCC's -aux-info option.  The following comment from
linknamespace.pl explains the caveats around this approach:

Here's an example of the output for ISO (C90) assert.h, from before my
recent fixes and whitelisting of cases that seem more complicated to
fix:

[initial] __assert_fail -> [libc.a(assert.o)] free -> [libc.a(malloc.o)] __get_nprocs -> [libc.a(getsysstats.o)] fgets_unlocked
[initial] __assert_fail -> [libc.a(assert.o)] __dcgettext -> [libc.a(dcgettext.o)] __dcigettext -> [libc.a(dcigettext.o)] __libc_setlocale_lock -> [libc.a(setlocale.o)] _nl_archive_subfreeres -> [libc.a(loadarchive.o)] __sysconf -> [libc.a(sysconf.o)] __tzname_max -> [libc.a(tzset.o)] __tzfile_compute -> [libc.a(tzfile.o)] fileno
[initial] __assert_fail -> [libc.a(assert.o)] __dcgettext -> [libc.a(dcgettext.o)] __dcigettext -> [libc.a(dcigettext.o)] __libc_setlocale_lock -> [libc.a(setlocale.o)] _nl_archive_subfreeres -> [libc.a(loadarchive.o)] __sysconf -> [libc.a(sysconf.o)] __tzname_max -> [libc.a(tzset.o)] __tzfile_compute -> [libc.a(tzfile.o)] fread_unlocked
[initial] __assert_fail -> [libc.a(assert.o)] __dcgettext -> [libc.a(dcgettext.o)] __dcigettext -> [libc.a(dcigettext.o)] __libc_setlocale_lock -> [libc.a(setlocale.o)] _nl_archive_subfreeres -> [libc.a(loadarchive.o)] __sysconf -> [libc.a(sysconf.o)] __tzname_max -> [libc.a(tzset.o)] __tzfile_compute -> [libc.a(tzfile.o)] ftello
[initial] __assert_fail -> [libc.a(assert.o)] free -> [libc.a(malloc.o)] malloc_info
[initial] __assert_fail -> [libc.a(assert.o)] __dcgettext -> [libc.a(dcgettext.o)] __dcigettext -> [libc.a(dcigettext.o)] __libc_setlocale_lock -> [libc.a(setlocale.o)] _nl_default_locale_path -> [libc.a(findlocale.o)] memmem
[initial] __assert_perror_fail -> [libc.a(assert-perr.o)] __strerror_r -> [libc.a(_strerror.o)] mempcpy
[initial] __assert_fail -> [libc.a(assert.o)] __dcgettext -> [libc.a(dcgettext.o)] __dcigettext -> [libc.a(dcigettext.o)] _nl_find_domain -> [libc.a(finddomain.o)] _nl_expand_alias -> [libc.a(localealias.o)] qsort -> [libc.a(msort.o)] qsort_r
[initial] __assert_fail -> [libc.a(assert.o)] _dl_pagesize -> [libc.a(dl-support.o)] __rawmemchr -> [libc.a(rawmemchr.o)] rawmemchr
[initial] __assert_fail -> [libc.a(assert.o)] __dcgettext -> [libc.a(dcgettext.o)] __dcigettext -> [libc.a(dcigettext.o)] __getcwd -> [libc.a(getcwd.o)] rewinddir
[initial] __assert_fail -> [libc.a(assert.o)] stderr
[initial] __assert_fail -> [libc.a(assert.o)] stderr -> [libc.a(stdio.o)] stdin
[initial] __assert_fail -> [libc.a(assert.o)] stderr -> [libc.a(stdio.o)] stdout
[initial] __assert_fail -> [libc.a(assert.o)] __dcgettext -> [libc.a(dcgettext.o)] __dcigettext -> [libc.a(dcigettext.o)] stpcpy
[initial] __assert_fail -> [libc.a(assert.o)] __fxprintf -> [libc.a(fxprintf.o)] _IO_vfprintf -> [libc.a(vfprintf.o)] __printf_fp -> [libc.a(printf_fp.o)] wmemset

Of the 161 XFAILs, seven are the inevitable varargs.h and ndbm.h
failures; I think the remaining 154 mostly represent genuine bugs in
glibc that should mostly be straightforward to fix (probably rather
fewer than 154 bugs - issues generally affect multiple headers, for
multiple standards).  (When fixing, of course you need to file a bug
in Bugzilla, and check for the possibility that the header
conditionals are what's incorrect - that the first listed symbol
shouldn't have been declared, or that the symbol finally brought in
should have been declared.)

	* conform/GlibcConform.pm: New file.
	* conform/conformtest.pl: Use GlibcConform module.
	* conform/linknamespace.pl: New file.
	* conform/list-header-symbols.pl: Likewise.
	* conform/Makefile (linknamespace-symlists-base): New variable.
	(linknamespace-symlists-tests): Likewise.
	(linknamespace-header-base): Likewise.
	(linknamespace-header-tests): Likewise.
	(tests-special): Add new tests.
	($(linknamespace-symlists-tests)): New rule.
	(linknamespace-libs): New variable.
	($(objpfx)symlist-stdlibs): New rule.
	($(linknamespace-header-tests)): Likewise.
	(test-xfail-XPG3/varargs.h/linknamespace): New variable.
	(test-xfail-XPG4/varargs.h/linknamespace): Likewise.
	(test-xfail-UNIX98/varargs.h/linknamespace): Likewise.
	(test-xfail-XPG4/ndbm.h/linknamespace): Likewise.
	(test-xfail-UNIX98/ndbm.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/ndbm.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/ndbm.h/linknamespace): Likewise.
	(test-xfail-ISO/math.h/linknamespace): Likewise.
	(test-xfail-ISO/signal.h/linknamespace): Likewise.
	(test-xfail-ISO/stdio.h/linknamespace): Likewise.
	(test-xfail-ISO/time.h/linknamespace): Likewise.
	(test-xfail-ISO99/complex.h/linknamespace): Likewise.
	(test-xfail-ISO99/ctype.h/linknamespace): Likewise.
	(test-xfail-ISO99/math.h/linknamespace): Likewise.
	(test-xfail-ISO99/signal.h/linknamespace): Likewise.
	(test-xfail-ISO99/stdio.h/linknamespace): Likewise.
	(test-xfail-ISO99/tgmath.h/linknamespace): Likewise.
	(test-xfail-ISO11/complex.h/linknamespace): Likewise.
	(test-xfail-ISO11/ctype.h/linknamespace): Likewise.
	(test-xfail-ISO11/math.h/linknamespace): Likewise.
	(test-xfail-ISO11/signal.h/linknamespace): Likewise.
	(test-xfail-ISO11/stdio.h/linknamespace): Likewise.
	(test-xfail-ISO11/tgmath.h/linknamespace): Likewise.
	(test-xfail-XPG3/ctype.h/linknamespace): Likewise.
	(test-xfail-XPG3/fnmatch.h/linknamespace): Likewise.
	(test-xfail-XPG3/glob.h/linknamespace): Likewise.
	(test-xfail-XPG3/math.h/linknamespace): Likewise.
	(test-xfail-XPG3/regex.h/linknamespace): Likewise.
	(test-xfail-XPG3/search.h/linknamespace): Likewise.
	(test-xfail-XPG3/stdio.h/linknamespace): Likewise.
	(test-xfail-XPG3/time.h/linknamespace): Likewise.
	(test-xfail-XPG3/unistd.h/linknamespace): Likewise.
	(test-xfail-XPG3/wordexp.h/linknamespace): Likewise.
	(test-xfail-XPG4/ctype.h/linknamespace): Likewise.
	(test-xfail-XPG4/fmtmsg.h/linknamespace): Likewise.
	(test-xfail-XPG4/fnmatch.h/linknamespace): Likewise.
	(test-xfail-XPG4/glob.h/linknamespace): Likewise.
	(test-xfail-XPG4/grp.h/linknamespace): Likewise.
	(test-xfail-XPG4/libgen.h/linknamespace): Likewise.
	(test-xfail-XPG4/math.h/linknamespace): Likewise.
	(test-xfail-XPG4/netdb.h/linknamespace): Likewise.
	(test-xfail-XPG4/pwd.h/linknamespace): Likewise.
	(test-xfail-XPG4/regex.h/linknamespace): Likewise.
	(test-xfail-XPG4/search.h/linknamespace): Likewise.
	(test-xfail-XPG4/stdio.h/linknamespace): Likewise.
	(test-xfail-XPG4/stdlib.h/linknamespace): Likewise.
	(test-xfail-XPG4/sys/mman.h/linknamespace): Likewise.
	(test-xfail-XPG4/sys/statvfs.h/linknamespace): Likewise.
	(test-xfail-XPG4/syslog.h/linknamespace): Likewise.
	(test-xfail-XPG4/time.h/linknamespace): Likewise.
	(test-xfail-XPG4/unistd.h/linknamespace): Likewise.
	(test-xfail-XPG4/wordexp.h/linknamespace): Likewise.
	(test-xfail-POSIX/aio.h/linknamespace): Likewise.
	(test-xfail-POSIX/fnmatch.h/linknamespace): Likewise.
	(test-xfail-POSIX/glob.h/linknamespace): Likewise.
	(test-xfail-POSIX/math.h/linknamespace): Likewise.
	(test-xfail-POSIX/mqueue.h/linknamespace): Likewise.
	(test-xfail-POSIX/pthread.h/linknamespace): Likewise.
	(test-xfail-POSIX/regex.h/linknamespace): Likewise.
	(test-xfail-POSIX/sched.h/linknamespace): Likewise.
	(test-xfail-POSIX/semaphore.h/linknamespace): Likewise.
	(test-xfail-POSIX/sys/mman.h/linknamespace): Likewise.
	(test-xfail-POSIX/time.h/linknamespace): Likewise.
	(test-xfail-POSIX/unistd.h/linknamespace): Likewise.
	(test-xfail-POSIX/wordexp.h/linknamespace): Likewise.
	(test-xfail-UNIX98/aio.h/linknamespace): Likewise.
	(test-xfail-UNIX98/ctype.h/linknamespace): Likewise.
	(test-xfail-UNIX98/fmtmsg.h/linknamespace): Likewise.
	(test-xfail-UNIX98/fnmatch.h/linknamespace): Likewise.
	(test-xfail-UNIX98/glob.h/linknamespace): Likewise.
	(test-xfail-UNIX98/grp.h/linknamespace): Likewise.
	(test-xfail-UNIX98/libgen.h/linknamespace): Likewise.
	(test-xfail-UNIX98/math.h/linknamespace): Likewise.
	(test-xfail-UNIX98/mqueue.h/linknamespace): Likewise.
	(test-xfail-UNIX98/netdb.h/linknamespace): Likewise.
	(test-xfail-UNIX98/pthread.h/linknamespace): Likewise.
	(test-xfail-UNIX98/pwd.h/linknamespace): Likewise.
	(test-xfail-UNIX98/regex.h/linknamespace): Likewise.
	(test-xfail-UNIX98/sched.h/linknamespace): Likewise.
	(test-xfail-UNIX98/search.h/linknamespace): Likewise.
	(test-xfail-UNIX98/semaphore.h/linknamespace): Likewise.
	(test-xfail-UNIX98/stdio.h/linknamespace): Likewise.
	(test-xfail-UNIX98/stdlib.h/linknamespace): Likewise.
	(test-xfail-UNIX98/sys/mman.h/linknamespace): Likewise.
	(test-xfail-UNIX98/sys/statvfs.h/linknamespace): Likewise.
	(test-xfail-UNIX98/syslog.h/linknamespace): Likewise.
	(test-xfail-UNIX98/time.h/linknamespace): Likewise.
	(test-xfail-UNIX98/unistd.h/linknamespace): Likewise.
	(test-xfail-UNIX98/wchar.h/linknamespace): Likewise.
	(test-xfail-UNIX98/wordexp.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/aio.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/complex.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/fcntl.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/fmtmsg.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/fnmatch.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/glob.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/grp.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/libgen.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/math.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/mqueue.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/net/if.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/netdb.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/pthread.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/pwd.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/regex.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/search.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/semaphore.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/signal.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/spawn.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/stdlib.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/sys/mman.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/sys/statvfs.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/sys/wait.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/syslog.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/tgmath.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/time.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/ucontext.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/unistd.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K/wordexp.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/aio.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/complex.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/ctype.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/dirent.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/fcntl.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/grp.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/math.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/mqueue.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/net/if.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/netdb.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/pthread.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/regex.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/semaphore.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/spawn.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/sys/mman.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/sys/statvfs.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/tgmath.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/time.h/linknamespace): Likewise.
	(test-xfail-POSIX2008/unistd.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/aio.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/complex.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/dirent.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/fcntl.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/fmtmsg.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/grp.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/libgen.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/math.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/mqueue.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/net/if.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/netdb.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/pthread.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/pwd.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/regex.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/search.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/semaphore.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/spawn.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/sys/mman.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/sys/statvfs.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/syslog.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/tgmath.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/time.h/linknamespace): Likewise.
	(test-xfail-XOPEN2K8/unistd.h/linknamespace): Likewise.