Use more precise return types for getimagesize and getimagesizefromst…

…ring

- Key 0 (the image width) is always positive
- Key 1 (the image height) is always positive
- Key 2 is always one of the `IMAGETYPE_*` constants

dictionaries/CallMap.php

@@ -3304,8 +3304,8 @@
 'gethostbyname' => ['string', 'hostname'=>'string'],
 'gethostbynamel' => ['list<string>|false', 'hostname'=>'string'],
 'gethostname' => ['string|false'],
-'getimagesize' => ['array{0:int, 1: int, 2: int, 3: string, mime: string, channels?: 3|4, bits?: int}|false', 'filename'=>'string', '&w_image_info='=>'array'],
-'getimagesizefromstring' => ['array{0:int, 1: int, 2: int, 3: string, mime: string, channels?: 3|4, bits?: int}|false', 'string'=>'string', '&w_image_info='=>'array'],
+'getimagesize' => ['array{0: positive-int, 1: positive-int, 2: IMAGETYPE_*, 3: string, mime: string, channels?: 3|4, bits?: int}|false', 'filename'=>'string', '&w_image_info='=>'array'],
+'getimagesizefromstring' => ['array{0: positive-int, 1: positive-int, 2: IMAGETYPE_*, 3: string, mime: string, channels?: 3|4, bits?: int}|false', 'string'=>'string', '&w_image_info='=>'array'],
 'getlastmod' => ['int|false'],
 'getmxrr' => ['bool', 'hostname'=>'string', '&w_hosts'=>'array<int, string>', '&w_weights='=>'array<int, int>'],
 'getmygid' => ['int|false'],