TYPO3 Core

Hey,

this is a pre-requisite for the mass uploader. I often find it difficult to always check if the upload_max_filesize or post_max_size is lower than the $TYPO3_CONF_VARS['BE']['maxFileSize']. I introduced this feature so we can use it all through the backend in various cases to have a unified check. I found that without this function, the devs who want to upload always need to check against the various PHP limitation himself.

(issue imported from #M10717)