Description:
------------
memory_get_usage does not work correctly with reflection calls such as invoke.

Test script:
---------------
<?php
 
class HelloWorld
{
 public function sayHelloTo($name)
 {
  $s = memory_get_usage();
 
  $something = str_repeat($name, pow(1024, 2));
 
  echo 'Inside: ';
  echo memory_get_usage() - $s.PHP_EOL;
 }
}
 
$reflectionMethod = new ReflectionMethod('HelloWorld', 'sayHelloTo');
 
$s = memory_get_usage();
 
 $reflectionMethod->invoke(new HelloWorld(), 'a');
 
echo 'Outside: ';
echo memory_get_usage() - $s;

Expected result:
----------------
Inside: 1048760
Outside: 1048760

Actual result:
--------------
Inside: 1048760
Outside: 92