Patching GMP for build-many-glibcs.py

[Joseph Myers]

build-many-glibcs.py fails to build host-libraries on systems using GCC 15 
because of a configure test incompatible with C23.  There has been no GMP 
release since this was fixed in January.  The natural fix probably 
involves providing a patched GMP tarball with the changes

changeset:   18477:8e7bb4ae7a18
user:        Marc Glisse <marc.glisse@inria.fr>
date:        Wed Jan 29 22:38:02 2025 +0100
files:       ChangeLog acinclude.m4
description:
Complete function prototype in acinclude.m4 for C23 compatibility

changeset:   18484:d66d66d82dbb
tag:         tip
user:        Marc Glisse <marc.glisse@inria.fr>
date:        Tue Apr 01 15:25:46 2025 +0200
files:       ChangeLog acinclude.m4
description:
Add parameter names to function prototype

backported, so that build-many-glibcs can download such a tarball until 
there is a new GMP release - where should we put such a tarball for use by 
build-many-glibcs.py?

-- 
Joseph S. Myers
josmyers@redhat.com