Correction for the fix for Bug 3508 - Persistent storage support breaks Linux compatibility.
A 2nd `make install' will fail attempting to create symlink libnvmemmory.so already created by 1st install.
Install should pre-emptively delete it.
/* Fudge unix isatty and fileno for RISCOS */
#include <stdio.h>
#include <time.h>
int fileno(FILE *f);
int isatty(int fn);
unsigned int unixtime(unsigned int ld,unsigned int ex);
int acorntime(unsigned int *ex, unsigned int *ld, time_t ut);
int isdir(char *fn);
int isfile(char *fn);
int object_exists(char *fn);