add test for getting invalid connection attributes

test/pdo_sqlsrv/pdo_get_attr_invalid.phpt

@@ -0,0 +1,38 @@
+--TEST--
+Test getting invalid attributes
+--SKIPIF--
+
+--FILE--
+<?php
+  
+require_once("autonomous_setup.php");
+
+try{
+$database = "tempdb";
+$dsn = 	"sqlsrv:Server = $serverName; Database = $database";
+
+$conn = new PDO( $dsn, $username, $password, array(PDO::ATTR_ERRMODE => PDO::ERRMODE_SILENT)); 
+   
+@$conn->getAttribute( PDO::ATTR_FETCH_TABLE_NAMES );
+print_r (($conn->errorInfo())[2]);
+echo "\n";
+
+@$conn->getAttribute( PDO::ATTR_CURSOR );
+print_r (($conn->errorInfo())[2]);
+echo "\n";
+
+@$conn->getAttribute( PDO::ATTR_CONNECTION_STATUS );
+print_r (($conn->errorInfo())[2]);
+echo "\n";
+}
+catch ( PDOException $e ){
+    exit;
+}
+
+?> 
+
+--EXPECT--
+
+An unsupported attribute was designated on the PDO object.
+The given attribute is only supported on the PDOStatement object.
+An invalid attribute was designated on the PDO object.