Description:
------------
preg_match_all can't match \S correctly

in php5.4 ~ php5.6.33

```
$matches = array();
$template = '<p>{{{ 发货单号 }}}</p><p>{{{ 单据123号 }}}</p><p>{{{ 拉包 }}}</p><p>{{{ a }}}</p><p>{{{ a }}}</p>';
$ret = preg_match_all('/\{\{\{ \S+ \}\}\}/', $template, $matches);
print_r($matches);
```

result is 
```
Array
(
    [0] => Array
        (
            [0] => {{{ 发货单号 }}}
            [1] => {{{ 单据123号 }}}
            [2] => {{{ a }}}
            [3] => {{{ a }}}
        )

)
```

the "拉包" is missing. i try many cases. "包" can't be matched by "\S".

but in php5.3 or other languages, "包" can be matched by "\S".




Test script:
---------------
$matches = array();
$template = '<p>{{{ 发货单号 }}}</p><p>{{{ 单据123号 }}}</p><p>{{{ 拉包 }}}</p><p>{{{ a }}}</p><p>{{{ a }}}</p>';
$ret = preg_match_all('/\{\{\{ \S+ \}\}\}/', $template, $matches);
print_r($matches);

Expected result:
----------------
Array
(
    [0] => Array
        (
            [0] => {{{ 发货单号 }}}
            [1] => {{{ 单据123号 }}}
            [2] => {{{ 拉包 }}}
            [3] => {{{ a }}}
            [4] => {{{ a }}}
        )

)

Actual result:
--------------
Array
(
    [0] => Array
        (
            [0] => {{{ 发货单号 }}}
            [1] => {{{ 单据123号 }}}
            [2] => {{{ a }}}
            [3] => {{{ a }}}
        )

)