generate .str() for all arrays

compiler/tests/mut_test.v

@@ -1,14 +1,14 @@
-fn foo(a mut []int) {
+fn foo(b int, a mut []int) {
 	a[0] = 7 
 	a << 4 
 } 
 
 // TODO 
 fn test_mut() {
-	mut a := [1,2,3] 
-	foo(mut a) 
+	mut numbers := [1,2,3] 
+	foo(7, numbers) 
 	//assert a.len == 4 
-	assert a[0] == 7 
+	assert numbers[0] == 7 
 	//assert a[3] == 4 
 
 	n := 1 

compiler/tests/str_gen_test.v

@@ -0,0 +1,16 @@
+struct Foo {
+	a int 
+} 
+
+fn test_array_str() {
+	f := Foo{34}
+	println(f) 
+	//s := f.str() 
+	//println(s) 
+	n := [i64(1), 2, 3] 
+	assert n.str() == '[1, 2, 3]' 
+	println(n)  // make sure the array is printable 
+	n2 := [4,5,6] 
+	assert n2.str() == '[4, 5, 6]' 
+	println(n2) 
+}