[PATCH] manual: Update alloca and variable length array documentation

[Florian Weimer]

I'm resubmitting my old documentation patch (from early 2016) for
reconsideration.

I reinstated the mention of GNU compiler compatibility for strdupa and
strndupa.

Thanks,
Florian
-------------- next part --------------
A non-text attachment was scrubbed...
Name: manual-alloca.patch
Type: text/x-patch
Size: 12411 bytes
Desc: not available
URL: <http://sourceware.org/pipermail/libc-alpha/attachments/20170811/c4e0a39d/attachment.bin>