6b18 build problems

[Matthias Klose]

seen some build problems with 6b18

  - ant-1.8 returns an error code != 0 calling ant -diagnostics,
    breaking the build. if this is intended, then we need a
    workaround in openjdk.

  - cacao build failure when configured with
      --with-openjdk=/usr/lib/jvm/java-6-openjdk
      --with-hotspot-build=original
      --with-additional-vms=cacao
    works with a two stage build using gcj.

    details:
 
http://launchpadlibrarian.net/39430688/buildlog_ubuntu-lucid-armel.openjdk-6_6b18~pre1-0ubuntu1_FAILEDTOBUILD.txt.gz

  - make jtregcheck starts rebuilding the whole openjdk again. apparently
    an out of date stamp, or a missing stamp. still searching for this one.
    any ideas?

Matthias