[RFC] Fix static-only build of glibc [BZ #20845]

[Joseph Myers]

On Tue, 9 Mar 2021, Carlos Eduardo Seo via Libc-alpha wrote:

> 'make' passes on x86_64-linux-gnu, aarch64-linux-gnu and 
> powerpc64le-linux-gnu.

Another key piece of validation is that a default build, without 
--disable-shared, is unaffected.

* The installation tree should be byte-for-byte identical before and after 
this patch, at least after stripping binaries if there are otherwise 
issues with line numbers in debug info, and eliminating timestamps in .a 
files as needed.  If any differences remain, they should be clearly 
explained.

* The testsuite should also complete with unchanged results in a default 
build.

-- 
Joseph S. Myers
joseph@codesourcery.com