Add some tests to increase code coverage

ext/spl/tests/fixedarray_010.phpt

@@ -1,12 +1,15 @@
 --TEST--
-SPL: FixedArray: Setting size to 0
+SPL: FixedArray: Setting size
 --FILE--
 <?php
 
-$a = new SplFixedArray(1);
+$a = new SplFixedArray(0);
+$a = new SplFixedArray(3);
 
 $a[0] = 1;
 
+$a->setSize(2);
+$a->setSize(3);
 $a->setSize(0);
 
 print "ok\n";

ext/spl/tests/fixedarray_017.phpt

@@ -0,0 +1,20 @@
+--TEST--
+SPL: FixedArray: var_dump
+--FILE--
+<?php
+$a = new SplFixedArray(2);
+$a[0] = "foo";
+var_dump(empty($a[0]), empty($a[1]), $a);
+?>
+--EXPECTF--
+bool(false)
+bool(true)
+object(SplFixedArray)#1 (1) {
+  [u"array":u"SplFixedArray":private]=>
+  array(2) {
+    [0]=>
+    unicode(3) "foo"
+    [1]=>
+    NULL
+  }
+}