check parent::__construct combination with trait requirements

Summary: With trait requirements, we can now make ensure that an
 ##__construct## in a trait calls the parent constructor of its
 ##require extends## class(es).

 Since we do separate checks for ## __construct ##, it makes sense to
 make sure that we've covered the case where a ## __construct ## is
 present in a class that uses a trait and provides a ##__construct##
 as well.

Reviewed By: @jwatzman

Differential Revision: D1396751
Fix Memcache::get($keys) when $keys is an array

Summary: Without this patch, the result of the test is:

array(2) {
  ["abcdef1"]=>
  string(13) "value:abcdef1"
  ["abcdef13"]=>
  string(14) "value:abcdef13"
}

This fix is needed for drupal (with the memcache module).
Closes #2994

Reviewed By: @ptarjan

Differential Revision: D1397189

Pulled By: @JoelMarcey
Disable test/slow/ext_xdebug/xdebug/peak_memory_usage.php

Summary: It's been flaking out on various diffs.

Reviewed By: @alexmalyshev

Differential Revision: D1398776
Converting ArrayObjcets to an array was not working correctly when the STD_PROP_LIST flag was set

Summary: The STD_PROP_LIST flag for array objects should treat properties of the array object as if they are the storage of the class. When we were converting to an array the internal storage array was still being copied. This also a problem with json_encoding where the properties were not being encoded. Fixes #2139

Reviewed By: @ptarjan

Differential Revision: D1382324