Fix sparc64 build with GCC 9 [committed]

[David Miller]

From: Joseph Myers <joseph@codesourcery.com>
Date: Tue, 13 Nov 2018 00:27:41 +0000

> Similar to the x86_64 and armv7 build issues, glibc fails to build for
> sparc64 with current mainline GCC because of aliases declared in the
> course of defining IFUNCs, which copy their attributes from a header
> declaration, ending up with fewer attributes than the (built-in)
> string function they alias.  This patch fixes the issue similarly to
> the fixes for those other architectures.
> 
> Tested with build-many-glibcs.py compilers build for
> sparc64-linux-gnu.  Committed.

Thank you.