fix gotest by fixing nm -s to print in file order by storing a sequence number

as the .6 file is read.   now tests will be run in file order.

R=rsc
DELTA=9  (6 added, 1 deleted, 2 changed)
OCL=27542
CL=27544

include/mach_amd64.h

@@ -85,6 +85,7 @@ struct	Sym
 	char	type;
 	char	*name;
 	char *gotype;
+	int	sequence;	// order in file
 };
 /*
  * End of Plan 9 a.out.h

src/cmd/nm/nm.c

@@ -185,11 +185,13 @@ cmp(void *vs, void *vt)
 
 	s = vs;
 	t = vt;
-	if(nflag)
+	if(nflag)	// sort on address (numeric) order
 		if((*s)->value < (*t)->value)
 			return -1;
 		else
 			return (*s)->value > (*t)->value;
+	if(sflag)	// sort on file order (sequence)
+		return (*s)->sequence - (*t)->sequence;
 	return strcmp((*s)->name, (*t)->name);
 }
 /*
@@ -298,7 +300,6 @@ printsyms(Sym **symptr, long nsym)
 	char *cp;
 	char path[512];
 
-	if(!sflag)
 	qsort(symptr, nsym, sizeof(*symptr), (void*)cmp);
 
 	wid = 0;

src/libmach_amd64/obj.c

@@ -108,6 +108,8 @@ static	void	objreset(void);
 static	void	objlookup(int, char *, int, uint);
 static	void 	objupdate(int, int);
 
+static	int	sequence;
+
 int
 objtype(Biobuf *bp, char **name)
 {
@@ -295,6 +297,7 @@ objlookup(int id, char *name, int type, uint sig)
 	sp->s.type = type;
 	sp->s.sig = sig;
 	sp->s.value = islocal(type) ? MAXOFF : 0;
+	sp->s.sequence = sequence++;
 	names[id] = &sp->s;
 	sp->next = hash[h];
 	hash[h] = sp;