bug#30730: JDK not reproducible

[Ricardo Wurmus]

The icedtea packages are not reproducible.

* The JDK provides jar files that did not undergo repacking (see
  ant-build-system), so they contain timestamps.

* The doc output contains files generated by javadoc, which contain
  more than one timestamp.  Near the top is a comment:

    <!-- Generated by javadoc (version …) on Tue Mar 06 12:59:50 GMT 2018 -->

  A little further down (still in the head of the document):

    <meta name="date" content="2018-03-06">

* Some of the HTML files in the doc output (such as
  
share/doc/icedtea/api/org/omg/PortableInterceptor/ORBInitInfoPackage/DuplicateNameHelper.html)
  also contain text like this:

--8<---------------cut here---------------start------------->8---
<div 
class="block">org/omg/PortableInterceptor/ORBInitInfoPackage/DuplicateNameHelper.java
 .
 Generated by the IDL-to-Java compiler (portable), version "3.2"
 from ../../../../src/share/classes/org/omg/PortableInterceptor/Interceptors.idl
 Tuesday, March 6, 2018 1:41:31 PM GMT</div>
--8<---------------cut here---------------end--------------->8---

* Some HTML files in the doc output have *lots* of differences.  An
  example is
  share/doc/icedtea/api/javax/print/attribute/standard/PrinterMakeAndModel.html,
  which seems to be *empty* in the “-check” output.  This is rather
  strange.


--
Ricardo