made some updates

bigint/tst/support.c

@@ -38,13 +38,13 @@ void fatalError(char *msg) {
  */
 void * newPrimObject(int dataSize) {
   ObjRef bigObjRef;
-
-  bigObjRef = malloc(sizeof(unsigned int) +
-                  dataSize * sizeof(unsigned char));
+  int size = sizeof(unsigned int) + dataSize * sizeof(unsigned char);
+  bigObjRef = malloc(size);
+  bigObjRef->size = size;
   if (bigObjRef == NULL) {
     fatalError("newPrimObject() got no memory");
   }
-  bigObjRef->size = dataSize;
+  bigObjRef->size = size;
   return bigObjRef;
 }