prefer (X ? 1 : -1) when converting from boolean (1,0) to int (1,-1)

[pspp] / lib / xstrtoul.c

#define __strtol strtoul
#define __strtol_t unsigned long int
#define __xstrtol xstrtoul
#define STRTOL_T_MINIMUM 0
#define STRTOL_T_MAXIMUM ULONG_MAX
#include "xstrtol.c"