Deprecate php4 style constructors

PHP7 is deprecating PHP4 style constructors, so we need to modify our code to have _construct methods that fire before the named PHP4 style constructors.  The PHP4 style constructors will call the PHP5 style constructor in case it is being called directly (usually via parent::METHOD).

This modifies external libraries to add PHP5 style constructors, but doesn't add a notice for when they are used.  In WordPress core code, PHP4 style constructors are being given a call to _deprecated_constructor. To the PHP4 style constructor I say "I know that I can't take no more | It ain't no lie | I wanna see you out that door | Baby, bye, bye, bye..."

Upstream: https://wiki.php.net/rfc/remove_php4_constructors

Props jdgrimes, netweb, jorbin
See #31982



git-svn-id: https://develop.svn.wordpress.org/trunk@32990 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/atomlib.php

@@ -87,7 +87,10 @@ class AtomParser {
     var $feed;
     var $current;
 
-    function AtomParser() {
+	/**
+	 * PHP5 constructor.
+	 */
+    function __construct() {
 
         $this->feed = new AtomFeed();
         $this->current = null;
@@ -95,6 +98,13 @@ class AtomParser {
         $this->map_xmlns_func = create_function('$p,$n', '$xd = "xmlns"; if(strlen($n[0])>0) $xd .= ":{$n[0]}"; return "{$xd}=\"{$n[1]}\"";');
     }
 
+	/**
+	 * PHP4 constructor.
+	 */
+	public function AtomParser() {
+		self::__construct();
+	}
+
     function _p($msg) {
         if($this->debug) {
             print str_repeat(" ", $this->depth * $this->indent) . $msg ."\n";