compile with Visual Studio 2017

Author: Daniel Kroening

src/big-int/bigint-test.cc

@@ -298,7 +298,7 @@ run_floorPow2_tests ()
 
   for (unsigned i = 0; i < 512; ++i) {
     unsigned x = 512 - i;
-    N = pow(2,x);
+    N = pow(BigInt(2),x);
     M.setPower2(x);
 
     if (!(N == M)) {
@@ -327,7 +327,7 @@ run_floorPow2_tests ()
 
   }
 
-  N = pow(2,0);  // 1
+  N = pow(BigInt(2),0);  // 1
   M.setPower2(0);
 
   if (!(N == M)) {