EZC: add stubs for some stream functions

* Merge main/php_streams.cpp and main/streams/streams.cpp. Only the
  latter has an equivalent .c file in PHP.
* Add stubs that unconditionally throw. Several of them were needed for
  Mongo to link without "undefined reference" errors. All the Mongo
  tests now pass, which tells you something about the test coverage.

Submitted on behalf of a third-party: The PHP Group
Source: PHP 5.6.0-dev
License: version 3.01 of the PHP license