Prevent parallel test conflicts

The better solution would be to actually use different directory names,
but adding respective CONFLICTS sections solves the issue for now.

Author: cmb69

ext/standard/tests/file/disk.phpt

@@ -8,6 +8,8 @@ if (substr(PHP_OS, 0, 3) == 'WIN') {
     die('skip not for Windows');
 }
 ?>
+--CONFLICTS--
+disk_total_space
 --FILE--
 <?php
 

ext/standard/tests/file/disk_total_space_basic.phpt

@@ -1,5 +1,7 @@
 --TEST--
 Test disk_total_space() function : basic functionality
+--CONFLICTS--
+disk_total_space
 --FILE--
 <?php
 /*

ext/standard/tests/file/disk_total_space_error-win32.phpt

@@ -5,6 +5,8 @@ Test disk_total_space() function : error conditions
 if(substr(PHP_OS, 0, 3) != 'WIN' )
   die("skip Valid only for Windows");
 ?>
+--CONFLICTS--
+disk_total_space
 --FILE--
 <?php
 /*

ext/standard/tests/file/disk_total_space_error.phpt

@@ -5,6 +5,8 @@ Test disk_total_space() function : error conditions
 if(substr(PHP_OS, 0, 3) == 'WIN')
   die("skip Not valid on Windows");
 ?>
+--CONFLICTS--
+disk_total_space
 --FILE--
 <?php
 /*

ext/standard/tests/file/disk_total_space_variation.phpt

@@ -1,5 +1,7 @@
 --TEST--
 Testing disk_total_space() functions : Usage Variations.
+--CONFLICTS--
+disk_total_space
 --FILE--
 <?php
 /*