Declare php_user_filter::$stream property

This property is temporarily set during the filter() call. I have
no idea why this wasn't added as an argument to filter() instead.

Declare tentative return types for ext/standard (#7065)

Fix return type of php_user_filter::onCreate()

Use typed properties in php_user_filter

Generate class entries from stubs for com, standard, xmlreader, xmlwriter, xsl, zip, Zend

Closes GH-6706

Add support for generating class entries from stubs

Closes GH-6289

Co-authored-by: Nikita Popov <nikita.ppv@gmail.com>

Add all the missing parameter types to stubs

Closes GH-5955

Use proper methods for php_user_filter implementation

These are dummy methods, but should at least check zpp for
arginfo consistency.

Generate function entries from stubs for a couple of extensions

Migrates ext/standard, ext/tidy, ext/tokenizer,
ext/xml, ext/xml_reader, and ext/xml_writer. Closes GH-5381.

Verify that all stubs have a return type

Do not include the same stub multiple times

Closes GH-5322