Try to support gcc 15 in our GMP dependency

depends/patches/libgmp/gcc-15.patch

@@ -0,0 +1,30 @@
+diff --git a/acinclude.m4 b/acinclude.m4
+index bcc6f52..53705e1 100644
+--- a/acinclude.m4
++++ b/acinclude.m4
+@@ -602,24 +602,6 @@ int f ()
+ }
+ ])
+ 
+-GMP_PROG_CC_WORKS_PART([$1], [long long reliability test 1],
+-[/* The following provokes a segfault in the compiler on powerpc-apple-darwin.
+-   Extracted from tests/mpn/t-iord_u.c.  Causes Apple's gcc 3.3 build 1640 and
+-   1666 to segfault with e.g., -O2 -mpowerpc64.  */
+-
+-#if defined (__GNUC__) && ! defined (__cplusplus)
+-typedef unsigned long long t1;typedef t1*t2;
+-void g(){}
+-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;}
+-void f(){static const struct{t1 n;t1 src[9];t1 want[9];}d[]={{1,{0},{1}},};t1 got[9];int i;
+-for(i=0;i<1;i++){if(e(got,got,9,d[i].n)==0)h();g(i,d[i].src,d[i].n,got,d[i].want,9);if(d[i].n)h();}}
+-#else
+-int dummy;
+-#endif
+-])
+-
+ GMP_PROG_CC_WORKS_PART([$1], [long long reliability test 2],
+ [/* The following provokes an internal compiler error on powerpc-apple-darwin.
+    Extracted from mpz/cfdiv_q_2exp.c.  Causes Apple's gcc 3.3 build 1640 and
+