parallel runs_merger: don't look for min_last_element in currently active blocks, just use the first element of the next block in the consume sequence as merge boundary value
parallel runs_merger: don't look for min_last_element in currently active blocks, just use the first element of the next block in the consume sequence as merge boundary value

git-svn-id: 4e7379b20b57f8e3dde5a0b7363f233184647162@2148 4e380d45-d1fd-0310-85a7-d18ec86df0ad

sriram-mahavadi/extlp,sriram-mahavadi/extlp,sriram-mahavadi/extlp,sriram-mahavadi/extlp