Description:
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Function class_alias cannot create alias for standard classes.

I'm using standard exceptions inspired by Java API for very long time. My exceptions was used earlier than exceptions introduced by SPL. I'd like to use SPL's exceptions instead of my exceptions in case they are defined, but I don't want to edit all codes to change exception names used. Therefor I'd like to use class_alias to act SPL exceptions as exceptions expected by applications.

Test script:
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<?php

class_alias('InvalidArgumentException', 'IllegalArgumentException');

// Application
throw new IllegalArgumentException('Arg must be abcd')

Expected result:
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thrown IllegalArgumentException

Actual result:
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PHP Warning: First argument of class_alias() must be a name of user defined class in aliases.php:17

Fatal error: Class 'IllegalArgumentException' not found in aliases.php on line 28