manual: Update @standards for [__]va_copy.

  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(-)
  

On 06/17/2017 04:42 AM, Rical Jasan wrote:
> 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.

Let's leave alone the question of whether we should document a GCC
extension for now.

This patch is OK with some additional wording adjustments: in the second
paragraph of the @deftypefn block, change "This macro" to
"@code{va_copy}", "@samp{gcc -ansi}" to "@samp{gcc -std=c90}", and "The
macro @code{__va_copy} is available as a GNU extension;" to "GCC
provides @code{__va_copy}, as an extension, in any standards mode."
Delete the clause beginning "before GCC 3.0", as I believe compilers
that old will no longer work with glibc's headers anyway.

zw
  

On Jun 17 2017, Zack Weinberg <zackw@panix.com> wrote:

> Delete the clause beginning "before GCC 3.0", as I believe compilers
> that old will no longer work with glibc's headers anyway.

We still support ancient GCC versions.

Andreas.