UPGRADING, UPGRADING.INTERNALS, and NEWS for SVG and extensible image API

NEWS

@@ -16,6 +16,8 @@ PHP                                                                        NEWS
 
 - Standard:
   . Add HEIF/HEIC support to getimagesize. (Benstone Zhang)
+  . Implement #71517 (Implement SVG support for getimagesize() and friends).
+    (nielsdos)
 
 - URI:
   . Empty host handling is fixed. (Máté Kocsis)

UPGRADING

@@ -246,6 +246,15 @@ PHP 8.5 UPGRADE NOTES
     ignored. This change affects only the sendmail transport.
   . getimagesize() now supports HEIF/HEIC images.
 
+- Standard:
+  . getimagesize() now supports SVG images when ext-libxml is also loaded.
+    Similarly, image_type_to_extension() and image_type_to_extension()
+    now also handle IMAGETYPE_SVG.
+  . The array returned by getimagesize() now has two additional entries:
+    "width_unit" and "height_unit" to indicate in which units the dimensions
+    are expressed. These units are px by default. They are not necessarily
+    the same (just to give one example: one may be cm and the other may be px).
+
 - XSL:
   . The $namespace argument of XSLTProcessor::getParameter(),
     XSLTProcessor::setParameter() and XSLTProcessor::removeParameter()
@@ -566,6 +575,9 @@ PHP 8.5 UPGRADE NOTES
   . T_VOID_CAST.
   . T_PIPE.
 
+- Standard:
+  . IMAGETYPE_SVG when libxml is loaded.
+
 ========================================
 11. Changes to INI File Handling
 ========================================

UPGRADING.INTERNALS

@@ -134,6 +134,10 @@ PHP 8.5 INTERNALS UPGRADE NOTES
   . The php_std_date() function has been removed. Use php_format_date() with
     the "D, d M Y H:i:s \\G\\M\\T" format instead.
   . Added php_url_encode_to_smart_str() to encode a URL to a smart_str buffer.
+  . The functionality of getimagesize(), image_type_to_mime_type(),
+    and image_type_to_extension() is now extensible using the internal APIs
+    php_image_register_handler() and php_image_unregister_handler() in
+    php_image.h.
 
 ========================
 4. OpCode changes