two uses of uninitialized memory,

picked up by valgrind.
fixes test/escape.go on linux.

R=ken
OCL=23971
CL=23971

src/cmd/6g/cgen.c

@@ -118,7 +118,7 @@ cgen(Node *n, Node *res)
 			p1 = gins(a, N, res);
 			p1->from = addr;
 		} else {
-			regalloc(&n2, n->type, &n1);
+			regalloc(&n2, n->type, N);
 			p1 = gins(a, N, &n2);
 			p1->from = addr;
 			gins(a, &n2, res);

src/cmd/6g/gsubr.c

@@ -1006,7 +1006,8 @@ gins(int as, Node *f, Node *t)
 void
 naddr(Node *n, Addr *a)
 {
-
+	a->scale = 0;
+	a->index = D_NONE;
 	a->type = D_NONE;
 	if(n == N)
 		return;