Add a patch to fix gmp build using GCC 15

See:

https://gmplib.org/list-archives/gmp-bugs/2025-February/005559.html
https://gmplib.org/repo/gmp/rev/8e7bb4ae7a18
https://gmplib.org/repo/gmp/rev/d66d66d82dbb

Author: jlaine

patches/gmp.patch

@@ -0,0 +1,11 @@
+--- gmp-6.3.0/configure	2023-07-29 15:42:22.000000000 +0200
++++ gmp/configure	2025-02-03 22:00:33.567817886 +0100
+@@ -6568,7 +6566,7 @@
+ 
+ #if defined (__GNUC__) && ! defined (__cplusplus)
+ typedef unsigned long long t1;typedef t1*t2;
+-void g(){}
++void g(int a,t1 const*b,t1 c,t2 d,t1 const*e,int f){}
+ void h(){}
+ static __inline__ t1 e(t2 rp,t2 up,int n,t1 v0)
+ {t1 c,x,r;int i;if(v0){c=1;for(i=1;i<n;i++){x=up[i];r=x+1;rp[i]=r;}}return c;}