gc: fix crash for nested complex division

R=ken2
CC=golang-dev
https://golang.org/cl/1720043

src/cmd/gc/cplx.c

@@ -184,6 +184,7 @@ complexgen(Node *n, Node *res)
 	case OINDEX:
 	case OIND:
 	case ONAME:	// PHEAP or PPARAMREF var
+	case OCALLFUNC:
 		igen(n, &n1, res);
 		complexmove(&n1, res);
 		regfree(&n1);
@@ -245,7 +246,6 @@ complexgen(Node *n, Node *res)
 	case OMUL:
 		complexmul(nl, nr, res);
 		break;
-	// ODIV call a runtime function
 	}
 }
 

test/ken/cplx4.go

@@ -35,4 +35,10 @@ func main() {
 	// real, imag, cmplx
 	c3 := cmplx(real(c2)+3, imag(c2)-5) + c2
 	fmt.Printf("c = %G\n", c3)
+
+	// compiler used to crash on nested divide
+	c4 := cmplx(real(c3/2), imag(c3/2))
+	if c4 != c3/2 {
+		fmt.Printf("c3 = %G != c4 = %G\n", c3, c4)
+	}
 }