Added forkjoin to partest's classpath to unbreak the build. No review.

git-svn-id: http://lampsvn.epfl.ch/svn-repos/scala/scala/trunk@22445 5e8d7ff9-d8ef-0310-90f0-a4852d11357a

build.xml

@@ -721,6 +721,7 @@ QUICK BUILD (QUICK)
         <pathelement location="${build-quick.dir}/classes/scalap"/>
         <pathelement location="${build-quick.dir}/classes/partest"/>
         <pathelement location="${ant.jar}"/>
+        <pathelement location="${lib.dir}/forkjoin.jar"/>
         <pathelement location="${scalacheck.jar}"/>
       </compilationpath>
     </scalacfork>