fix 386/arm builds

R=rsc
APPROVED=rsc
DELTA=2  (2 added, 0 deleted, 0 changed)
OCL=33640
CL=33645

src/cmd/5l/pass.c

@@ -138,6 +138,7 @@ dodata(void)
 
 	xdefine("setR12", SDATA, 0L+BIG);
 	xdefine("bdata", SDATA, 0L);
+	xdefine("data", SBSS, 0);
 	xdefine("edata", SDATA, datsize);
 	xdefine("end", SBSS, datsize+bsssize);
 	xdefine("etext", STEXT, 0L);

src/cmd/8l/pass.c

@@ -134,6 +134,7 @@ dodata(void)
 		s->value = bsssize + datsize;
 		bsssize += t;
 	}
+	xdefine("data", SBSS, 0);
 	xdefine("edata", SBSS, datsize);
 	xdefine("end", SBSS, bsssize + datsize);
 }