Extract file comparison into utility func

programs/util.h

@@ -174,6 +174,7 @@ int UTIL_isRegularFile(const char* infilename);
 int UTIL_setFileStat(const char* filename, stat_t* statbuf);
 U32 UTIL_isDirectory(const char* infilename);
 int UTIL_getFileStat(const char* infilename, stat_t* statbuf);
+int UTIL_isSameFile(const char* file1, const char* file2);
 
 U32 UTIL_isLink(const char* infilename);
 #define UTIL_FILESIZE_UNKNOWN  ((U64)(-1))