builtin: move array.data to the top of the struct

vlib/builtin/array.v

@@ -10,14 +10,14 @@ import strings
 // which avoids using generics and thus without generating extra
 // code for every type.
 pub struct array {
-pub:
-	element_size int // size in bytes of one element in the array.
 pub mut:
 	data   voidptr
 	offset int // in bytes (should be `usize`), to avoid copying data while making slices, unless it starts changing
 	len    int // length of the array in elements.
 	cap    int // capacity of the array in elements.
 	flags  ArrayFlags
+pub:
+	element_size int // size in bytes of one element in the array.
 }
 
 [flag]