Fix slice indexing in example

examples/arrays_and_slices.kl

@@ -33,7 +33,6 @@ main :: (): int
   // We set all variables to 1 so
   assert(static_array[6] == 1)
 
-
   // This is how slice is defined, no [] index in between brackets
   // slice is array pointer + length
   // Other then that it works exactly like regular array
@@ -41,4 +40,11 @@ main :: (): int
 
   // We can't do a compile time assert anymore
   assert(length_of(slice) == 8)
+  assert(slice[4] == 1)
 
+  // After we loop and reassign slice values
+  // old static_array gets changed
+  for slice
+    *it = 2
+  
+  assert(static_array[2] == 2)