[RFC PATCH] Disable uninitialized warnings around va_arg(, long double)

[Florian Weimer]

* Zack Weinberg:

> My changes to vfprintf in that patchset tickle a bug in the
> PowerPC-SPE back end, leading to spurious "used uninitialized"
> warnings--not on any code we control, but on a scratch variable
> emitted as part of the expansion of __builtin_va_arg!  This is
> <https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84772>, Jakub already
> has a fix in hand, and I'm not sure whether it's worth bothering to
> include these DIAG_IGNOREs in our tree.  I suppose it depends on
> whether the bug manifests in compilers older than 7.3 as well.

Will the default configuration of build-many-glibcs.py pick up a GCC
fix if it is backported to earlier release branches?  If yes, then I
don't think we need to work around it in the glibc tree.  The GCC will
eventually be able to powerpcspe users through a GCC release, and
until then, they can build with --disable-werror.