manual: Update @standards for [__]va_copy.

[Rical Jasan]

There is question as to whether __va_copy should be documented in the
glibc manual at all.  Since users searching for *va_copy are likely to
find this manual, and GCC doesn't document either, it is important we
continue to provide some kind of reference.

stdarg(3) documents va_copy as being introduced in C99.

	* lang.texi (va_copy): Change standard from ISO to C99.
	(__va_copy): Add standard and header annotation.
---
 manual/lang.texi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-manual-Update-standards-for-__-va_copy.patch
Type: text/x-patch
Size: 609 bytes
Desc: not available
URL: <http://sourceware.org/pipermail/libc-alpha/attachments/20170617/0ec9ad46/attachment.bin>