Issue #1748880 by mikeytown2: Only clear the stat cache for the files we care about.

core/includes/image.inc

core/lib/Drupal/Component/Archiver/ArchiveTar.php

...al/Component/PhpStorage/MTimeProtectedFastFileStorage.php

core/lib/Drupal/Core/StreamWrapper/LocalStream.php

...ules/file/lib/Drupal/file/Tests/FileFieldRevisionTest.php

...ules/system/lib/Drupal/system/Tests/File/FileTestBase.php

core/modules/user/lib/Drupal/user/Tests/UserPictureTest.php