Deprecate ArrayStatement and ResultCacheStatement

UPGRADE.md

 # Upgrade to 2.11
 
+## Deprecated `ArrayStatement` and `ResultCacheStatement` classes.
+
+The `ArrayStatement` and `ResultCacheStatement` classes are deprecated. In a future major release they will be renamed and marked internal as implementation details of the caching layer.
+
 ## Deprecated `ResultStatement` interface
 
 1. The `ResultStatement` interface is deprecated. Use the `Driver\Result` and `Abstraction\Result` interfaces instead.

lib/Doctrine/DBAL/Cache/ArrayStatement.php

@@ -16,6 +16,9 @@ use function array_values;
 use function count;
 use function reset;
 
+/**
+ * @deprecated
+ */
 class ArrayStatement implements IteratorAggregate, ResultStatement, Result
 {
     /** @var mixed[] */

lib/Doctrine/DBAL/Cache/ResultCacheStatement.php

@@ -32,6 +32,8 @@ use function reset;
  *
  * Also you have to realize that the cache will load the whole result into memory at once to ensure 2.
  * This means that the memory usage for cached results might increase by using this feature.
+ *
+ * @deprecated
  */
 class ResultCacheStatement implements IteratorAggregate, ResultStatement, Result
 {