access() not included in inquire.c

[gian-didom]

When compiling the library for MacOS, the following lines gives a compilation error:

inquire.c:

[...]
	{	byfile=1;
		g_char(a->infile,a->infilen,buf);
#ifdef NON_UNIX_STDIO
		x = access(buf,0) ? -1 : 0;
		for(i=0,p=NULL;i<MXUNIT;i++)
			if(f__units[i].ufd != NULL
			 && f__units[i].ufnm != NULL
			 && !strcmp(f__units[i].ufnm,buf)) {
				p = &f__units[i];
				break;
				}
[...]

The access function is not defined as the unistd.h file is never included.