Fix tests when running without mbstring

Zend/tests/declare_001.phpt

@@ -1,5 +1,11 @@
 --TEST--
 Testing declare statement with several type values
+--SKIPIF--
+<?php
+if (!extension_loaded("mbstring")) {
+  die("skip Requires ext/mbstring");
+}
+?>
 --INI--
 zend.multibyte=1
 --FILE--
@@ -17,8 +23,8 @@ print 'DONE';
 --EXPECTF--
 Warning: Unsupported encoding [1] in %sdeclare_001.php on line %d
 
-Warning: Unsupported encoding [1.1231312321313E+18] in %sdeclare_001.php on line %d
+Warning: Unsupported encoding [1123131232131312321] in %sdeclare_001.php on line %d
 
 Warning: Unsupported encoding [] in %sdeclare_001.php on line %d
 
-Fatal error: Cannot use constants as encoding in %sdeclare_001.php on line %d
+Fatal error: Cannot use constants as encoding in %sdeclare_001.php on line %d

Zend/tests/declare_002.phpt

@@ -5,6 +5,9 @@ Testing declare statement with several type values
 if (!ini_get("zend.multibyte")) {
   die("skip Requires zend.multibyte=1");
 }
+if (!extension_loaded("mbstring")) {
+  die("skip Requires ext/mbstring");
+}
 ?>
 --FILE--
 <?php

Zend/tests/declare_003.phpt

@@ -0,0 +1,23 @@
+--TEST--
+Testing declare statement with several type values
+--INI--
+zend.multibyte=1
+--FILE--
+<?php
+
+declare(encoding = 1);
+declare(encoding = 1123131232131312321);
+declare(encoding = NULL);
+declare(encoding = M_PI);
+
+print 'DONE';
+
+?>
+--EXPECTF--
+Warning: Unsupported encoding [1] in %sdeclare_003.php on line %d
+
+Warning: Unsupported encoding [1123131232131312321] in %sdeclare_003.php on line %d
+
+Warning: Unsupported encoding [] in %sdeclare_003.php on line %d
+
+Fatal error: Cannot use constants as encoding in %sdeclare_003.php on line %d

Zend/tests/declare_004.phpt

@@ -0,0 +1,27 @@
+--TEST--
+Testing declare statement with several type values
+--SKIPIF--
+<?php
+if (!ini_get("zend.multibyte")) {
+  die("skip Requires zend.multibyte=1");
+}
+?>
+--FILE--
+<?php
+
+declare(encoding = 1);
+declare(encoding = 1123131232131312321);
+declare(encoding = NULL);
+declare(encoding = M_PI);
+
+print 'DONE';
+
+?>
+--EXPECTF--
+Warning: Unsupported encoding [%d] in %sdeclare_004.php on line 3
+
+Warning: Unsupported encoding [%f] in %sdeclare_004.php on line 4
+
+Warning: Unsupported encoding [] in %sdeclare_004.php on line 5
+
+Fatal error: Cannot use constants as encoding in %sdeclare_004.php on line 6