[skip-ci] Update UPGRADING documents for the new argument for fputcsv()

Author: Girgias

UPGRADING

@@ -128,6 +128,12 @@ PHP 8.1 UPGRADE NOTES
     reference representation since PHP 7.0.
   . debug_zval_dump() will not print "interned" instead of a dummy refcount of
     one for interned strings and immutable arrays.
+  . fputcsv() now accepts a new "eol" argument which allow to define a custom
+    eol sequence, the default remains the same and is "\n".
+
+- SPL:
+  . SplFileObject::fputcsv() now accepts a new "eol" argument which allow to
+    define a custom eol sequence, the default remains the same and is "\n".
 
 ========================================
 2. New Features

UPGRADING.INTERNALS

@@ -83,3 +83,7 @@ PHP 8.1 INTERNALS UPGRADE NOTES
       of char* for the optional sequence/table name.
     - The php_pdo_str_tolower_dup() PDO_API has been removed use zend_str_tolower_dup()
       or zend_string_tolower_ex().
+
+  c. ext/standard
+    - The PHP API php_fputcsv() now takes an extra zend_string* argument at the end
+      for a custom EOL sequence, passing NULL provides the old default of "\n".