[js] make Browser.get_supported function private and inline instead of public, as I suppose it was meant to be like that

std/js/Browser.hx

@@ -44,7 +44,7 @@ class Browser {
 	 * environment such as node.js.
 	 */
 	public static var supported(get, never):Bool;
-	public static function get_supported() return untyped __js__("typeof window != \"undefined\"");
+	inline static function get_supported() return untyped __js__("typeof window != \"undefined\"");
 
 	/**
 	 * Safely gets the browser's local storage, or returns null if localStorage is unsupported or