Fix test cases which fail on Windows debug builds

We use the portable {TMP} instead of the hard-coded /tmp, and skip
mysqli_debug_append.phpt on Windows, because unlinking the trace file
while the connection is still open won't work there.

(cherry picked from commit 60081ca)

Author: cmb69

ext/mysqli/tests/mysqli_debug_append.phpt

@@ -17,6 +17,8 @@ if (defined('MYSQLI_DEBUG_TRACE_ENABLED') && !MYSQLI_DEBUG_TRACE_ENABLED)
 
 if (!$IS_MYSQLND)
 	die("SKIP Libmysql feature not sufficiently spec'd in MySQL C API documentation");
+
+if (substr(PHP_OS, 0, 3) == 'WIN') die("skip this test is not for Windows platforms");
 ?>
 --FILE--
 <?php

ext/mysqli/tests/mysqli_store_result_buffered_c.phpt

@@ -7,7 +7,7 @@ require_once('skipifemb.inc');
 require_once('skipifconnectfailure.inc');
 ?>
 --INI--
-mysqlnd.debug=d:t:O,/tmp/mysqlnd.trace
+mysqlnd.debug=d:t:O,{TMP}/mysqlnd.trace
 --FILE--
 <?php
 	require_once("connect.inc");

ext/mysqli/tests/mysqli_store_result_copy.phpt

@@ -10,7 +10,7 @@ if (!$IS_MYSQLND) {
 }
 ?>
 --INI--
-mysqlnd.debug=d:t:O,/tmp/mysqlnd.trace
+mysqlnd.debug=d:t:O,{TMP}/mysqlnd.trace
 mysqlnd.net_read_buffer_size=1
 mysqlnd.mempool_default_size=1
 mysqlnd.fetch_data_copy=0