Eclipse Jar Package Extract out system.js string and Boolean definition semicolon dispensable?

Org.eclipse.wst.jsdt.core_1.3.300.v201410221502\libraries\system.js
/**
* Object String ()
* @constructor
* @extends Object
* @since Standard ECMA-262 3rd. Edition
* @since Level 2 Document Object Model Core Definition.
*/
function String () {}
String.prototype = new Object ();

/**
* Object number ()
* @constructor
* @extends Object
* @since Standard ECMA-262 3rd. Edition
* @since Level 2 Document Object Model Core Definition.
*/
function number () {}
Number.prototype = new Object ();

/**
* Object Boolean ()
* @constructor
* @extends Object
* @since Standard ECMA-262 3rd. Edition
* @since Level 2 Document Object Model Core Definition.
*/
function Boolean () {};
Boolean.prototype = new Object ();

/**
* Object Date (s)
* @constructor
* @param {String} s
* @extends Object
* @since Standard ECMA-262 3rd. Edition
* @since Level 2 Document Object Model Core Definition.
*/
function Date (s) {};
Date.prototype = new Object ();

A semicolon is followed by a Boolean and date declaration after curly braces, and string and number do not? Is this for Mao?
This is the System.js file extracted from the jar package in Eclipse.

Eclipse's jar package extract the System.js string with the Boolean definition semicolon dispensable?