Added rough support for dejagnu testing. Changes need to be made to autoconf...

Added rough support for dejagnu testing. Changes need to be made to autoconf to provide the target_triplet and to check for 'grep -C' which would be used instead of the python script we have now. Eventually the python script should be converted to bash.
The dejagnu-clean needs to be fixed to use find.

llvm-svn: 17555