Move PHJ functions to IR file.

This patch only moves the ProcessBatch functions to the new file and
but doesn't make any changes to the functions. This will make rebasing
with my codegen patch much easier.

Change-Id: I0c45d64c743292e49714b7f86d4ab28c231c75ab
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/4225
Reviewed-by: Nong Li <nong@cloudera.com>
Reviewed-by: Ippokratis Pandis <ipandis@cloudera.com>
Tested-by: Skye Wanderman-Milne <skye@cloudera.com>