Description:
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While inspecting the class_alias() functionality I discovered that when declaring an alias of a class, it invokes an __autoload routine for all base class tree even if the aliased class not used in code. It may be inappropriate for huge frameworks when them used for quick/small/performance scripts that does not need alias functionality.

Test script:
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A.php:
class A { }
B.php:
class B extends A { }
C1.php:
class C1 extends B { }
C2.php:
class C2 extends B { }

main.php:
function __autoload($className) { include($className . '.php'); }
function included_files() { return implode(', ', array_map('basename', get_included_files())) . "\n"; }
    
    echo included_files();
    class_alias('C1', 'C');
    echo included_files();
    $c = new C();
    echo included_files();


Expected result:
----------------
main.php
main.php
main.php, C1.php, B.php, A.php

Actual result:
--------------
main.php
main.php, C1.php, B.php, A.php
main.php, C1.php, B.php, A.php