Mark a constant array const in jvp_dtoa.c

c/jv_dtoa.c

@@ -867,7 +867,7 @@ pow5mult
 {
 	Bigint *b1, *p5, *p51;
 	int i;
-	static int p05[3] = { 5, 25, 125 };
+	static const int p05[3] = { 5, 25, 125 };
 
 	if ((i = k & 3))
 		b = multadd(C, b, p05[i-1], 0);