Remove -1 crop mode

Author: nikic

UPGRADING

@@ -53,6 +53,8 @@ PHP 8.0 UPGRADE NOTES
     RFC: https://wiki.php.net/rfc/image2wbmp
   . The deprecated functions png2wbmp() and jpeg2wbmp() have been removed.
     RFC: https://wiki.php.net/rfc/deprecate-png-jpeg-2wbmp
+  . The default $mode parameter of imagecropauto() no longer accepts -1.
+    IMG_CROP_DEFAULT should be used instead.
 
 - GMP:
   . gmp_random() has been removed. One of gmp_random_range() or

ext/gd/gd.c

@@ -4452,10 +4452,6 @@ PHP_FUNCTION(imagecropauto)
 	}
 
 	switch (mode) {
-		case -1:
-			php_error_docref(NULL, E_DEPRECATED, "Crop mode -1 is deprecated. Use IMG_CROP_DEFAULT instead.");
-			mode = GD_CROP_DEFAULT;
-			/* FALLTHRU */
 		case GD_CROP_DEFAULT:
 		case GD_CROP_TRANSPARENT:
 		case GD_CROP_BLACK: