linter: added support for chains of instanceof

[i582]

Added support for:

/**
  * @param mixed $a
  */
function f1($a) {
  if ($a instanceof Foo || $a instanceof Boo) {
     exprtype($a, "\Boo|\Foo");
  }
}

/**
  * @param Boo|Foo|Zoo $a
  */
function f1($a) {
   if ($a instanceof Foo && $a instanceof Boo) {
     exprtype($a, "\Boo|\Foo");
   } else {
     exprtype($a, "\Zoo");
   }
}

And for:

/**
  * @param mixed $a
  */
function f($a) {
   if (!$a instanceof Foo) {
      return;
   }

   exprtype($a, "\Foo");
}

Fixes #339
Fixes #363
#346
#1037