Remove __libc_creat function name.

glibc has lots of __libc_* function names that no longer serve any
purpose (are not used for any calls or exported at a public symbol
version).  This patch removes __libc_creat.  It has the effect of
creat becoming a strong symbol instead of a weak symbol in various
cases, but that's fine; in shared libraries it doesn't matter at all,
while for static linking the only other symbol sometimes defined in
the same object is creat64, and whenever creat64 is a reserved name so
is creat.

Other such cases of unnecessary __libc_* symbols are expected to be
dealt with in separate patches over time.

Tested for x86_64 (testsuite, and that the disassembly of installed
shared libraries is unchanged by the patch).

	* include/fcntl.h (__libc_creat): Remove declaration.
	* io/creat.c (__libc_creat): Rename to creat.
	(creat): Do not define as alias.
	* sysdeps/unix/sysv/linux/alpha/creat.c (creat64): Define as alias
	of creat instead of __libc_creat.
	* sysdeps/unix/sysv/linux/generic/creat.c (__libc_creat): Rename
	to creat.
	(creat): Do not define as alias.
	[__WORDSIZE == 64] (creat64): Define as alias of creat instead of
	__libc_creat.
	* sysdeps/unix/sysv/linux/syscalls.list (creat): Do not define
	__libc_creat name.
	* sysdeps/unix/sysv/linux/wordsize-64/syscalls.list (creat):
	Likewise.
Clean up wchar_t conversion code in iconv program.
Remove __libc_readv and __libc_writev function names.

Continuing the removal of __libc_* function names that are no longer
used anywhere, this patch removes the __libc_readv and __libc_writev
names.

Tested for x86_64 that stripped installed shared libraries are
unchanged by the patch.

	* include/sys/uio.h (__libc_readv): Remove declaration.
	(__libc_writev): Likewise.
	* misc/readv.c (__libc_readv): Rename to __readv.
	(__readv): Do not define as alias.
	(readv): Define as alias of __readv.
	* misc/writev.c (__libc_writev): Rename to __writev.
	(__writev): Do not define as alias.
	(writev): Define as alias of __writev.
	* sysdeps/posix/readv.c (__libc_readv): Rename to __readv.
	(__readv): Do not define as alias.
	(readv): Define unconditionally as alias of __readv.
	* sysdeps/posix/writev.c (__libc_writev): Rename to __writev.
	(__writev): Do not define as alias.
	(writev): Define unconditionally as alias of __writev.
	* sysdeps/unix/syscalls.list (readv): Do not define __libc_readv
	name.
	(writev): Do not define __libc_writev name.
Clean up internal ctype.h header.