Description: Use int64_t instead of signed long int for 64-bit integer typedef.
On 32-bit architectures, longs are only 32 bits. The resulting overflow was
causing an infinite loop in the 0602ResultantFanProjection test.

References:
https://github.com/sagemath/sage/issues/32088
https://salsa.debian.org/math-team/gfan/-/commit/acaaa70
https://github.com/void-linux/void-packages/pull/34182

Author: Doug Torrance <dtorrance@piedmont.edu>

--- a/src/vektor.h
+++ b/src/vektor.h
@@ -10,7 +10,7 @@
 
 using namespace std;
 
-typedef signed long int int64;
+typedef int64_t int64;
 
 void outOfRange(int i, int n);
