RequireOnlyStandaloneIncrementAndDecrementOperatorsSniff: More tests

Author: kukulich

tests/Sniffs/Operators/data/requireOnlyStandaloneIncrementAndDecrementOperatorsNoErrors.php

@@ -30,3 +30,8 @@ function ($x) {
 ++$x;
 $x--;
 --$x;
+
+$a['a']++;
+++$a['a'];
+$a['a']--;
+--$a['a'];