This PR adds a missing PHPDoc type to the $table property of the JoinClause class.

The $table property will be of type Illuminate\Database\Query\Expression when DB::table()->joinSub() is called. Stack trace:

1. function joinSub():
   

   framework/src/Illuminate/Database/Query/Builder.php

   Line 613 in d8a5f1d

   return $this->join(new Expression($expression), $first, $operator, $second, $type, $where);

2. function join():
   

   framework/src/Illuminate/Database/Query/Builder.php

   Line 549 in d8a5f1d

   $join = $this->newJoinClause($this, $type, $table);

3. function newJoinClause():
   

   framework/src/Illuminate/Database/Query/Builder.php

   Line 781 in d8a5f1d

   return new JoinClause($parentQuery, $type, $table);

4. function __construct():
   

   framework/src/Illuminate/Database/Query/JoinClause.php

   Line 61 in d8a5f1d

   $this->table = $table;