minor #4046 Token - Added fast isset() path to token->equals() (staabm)
minor #4046 Token - Added fast isset() path to token->equals() (staabm)

This PR was merged into the 2.12 branch.

Discussion
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Token - Added fast isset() path to token->equals()

looking up the existance of a property via isset() is waaaaay faster then array_key_exists().
we still need array_key_exists() as a fallback, when properties exist with a null-value to work properly. this case is very rare, therefore this can be considered a speedup.

this change speeds up php-cs-fixer by 5.6%.

![image](https://user-images.githubusercontent.com/120441/46920181-bd4c6f00-cfea-11e8-8145-069ff58f63c4.png)

Commits
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577a46ab Added fast isset() path to token->equals()

SpacePossum/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,SpacePossum/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer,GrahamCampbell/PHP-CS-Fixer,kubawerlos/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,keradus/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,FriendsOfPHP/PHP-CS-Fixer,gharlan/PHP-CS-Fixer,Slamdunk/PHP-CS-Fixer,keradus/PHP-CS-Fixer