Delete an outdated comment for read_property and read_dimension

[sj-i]

The comment is outdated as of PHP7.
For example, in the current code, zend_assign_op_overloaded property() expects the refcount of the returned value from read_property to be greater than 0 when the returned value is a refcounted, to call zval_ptr_dtor() later.

This is a follow-up of #6597.

History

• The same description was originally written in a commit in 2004 alongside the write side. c8c0e97
• One requested to put the description in somewhere. https://externals.io/message/7789
• Then it was added as a comment in zend_object_handler.h . 7d3215d
• At the time the comment was written, there were at least three places where the code actually set the reference count to 0 in read_properties.

  • php-src/ext/dom/php_dom.c

    Line 229 in 7d3215d

    retval->refcount = 0;

  • php-src/ext/mysqli/mysqli.c

    Line 190 in 7d3215d

    retval->refcount = 0;

  • php-src/ext/simplexml/simplexml.c

    Line 245 in 7d3215d

    return_value->refcount = 0;

• All three of the above were removed during the development of PHP 7.
  • 2f0a758
  • 2402d6c
  • a975c7e
• In the current code, even when they generate and return a refcounted value, its refcount would be 1.