Add patch fixing MPIR (2.7.0.alpha12) 'configure' failure with GCC 5.…

…x (#18247)

Reduced patch (only patching acinclude.m4) submitted upstream.

build/pkgs/mpir/patches/fix_configure_with_GCC_5.x.patch

@@ -0,0 +1,37 @@
+Fix 'configure' test that fails with GCC 5.x just because it now defaults
+to standard C inline semantics.  (See Sage trac #18247.)
+
+--- mpir-2.7.0/acinclude.m4	2014-09-14 21:59:12.000000000 +0200
++++ mpir-2.7.0/acinclude.m4	2015-04-26 19:49:14.603554112 +0200
+@@ -584,6 +584,9 @@
+
+ #if defined(__GNUC__) && !defined(__clang__)
+ typedef unsigned long long t1;typedef t1*t2;
++#if defined(__GNUC_STDC_INLINE__) /* e.g. GCC 5.x defaults to this, not __GNUC_GNU_INLINE__ */
++extern
++#endif
+ __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;}
+ f(){static const struct{t1 n;t1 src[9];t1 want[9];}d[]={{1,{0},{1}},};t1 got[9];int i;
+--- mpir-2.7.0/configure	2014-09-14 21:59:13.000000000 +0200
++++ mpir-2.7.0/configure	2015-04-26 19:49:48.220468890 +0200
+@@ -5663,6 +5663,9 @@
+
+ #if defined(__GNUC__) && !defined(__clang__)
+ typedef unsigned long long t1;typedef t1*t2;
++#if defined(__GNUC_STDC_INLINE__) /* e.g. GCC 5.x defaults to this, not __GNUC_GNU_INLINE__ */
++extern
++#endif
+ __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;}
+ f(){static const struct{t1 n;t1 src[9];t1 want[9];}d[]={{1,{0},{1}},};t1 got[9];int i;
+@@ -6977,6 +6980,9 @@
+
+ #if defined(__GNUC__) && !defined(__clang__)
+ typedef unsigned long long t1;typedef t1*t2;
++#if defined(__GNUC_STDC_INLINE__) /* e.g. GCC 5.x defaults to this, not __GNUC_GNU_INLINE__ */
++extern
++#endif
+ __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;}
+ f(){static const struct{t1 n;t1 src[9];t1 want[9];}d[]={{1,{0},{1}},};t1 got[9];int i;