[PATCH] Add build option to disable usage of scv on powerpc

[Joseph Myers]

On Wed, 2 Jun 2021, Matheus Castanho via Libc-alpha wrote:

> Commit 68ab82f566 added support for the scv syscall ABI on powerpc.  Since then
> systems that have kernel and processor support started using scv.  However
> adding the proper support for a new syscall ABI requires changes to several
> other projects (e.g. qemu, valgrind, strace, kernel), which are gradually
> receiving support.
> 
> Meanwhile, having a way to disable scv on glibc at build time can be useful for
> distros that may encounter conflicts with projects that still do not support the
> scv ABI, buying time until proper support is added.
> 
> This commit adds a --disable-scv option that disables scv support and uses sc
> for all syscalls, just like before commit 68ab82f566.

New configure options should be documented in install.texi (and INSTALL 
regenerated).

-- 
Joseph S. Myers
joseph@codesourcery.com