message: Add merge_rows instruction to AFL.
diff: @@ -69,6 +69,7 @@ enum INS {
  REMOVE_COLUMN,
  SET,
  REMOVE_ROW,
  + MERGE_ROWS,
  ADD_COLUMN_LINK,
  ADD_COLUMN_LINK_LIST,
  CLEAR_TABLE,
  @@ -593,6 +594,22 @@ void parse_and_apply_instructions(std::string& in, const std::string& path, util
  t->remove(row_ndx);
  }
  }
  + else if (instr == MERGE_ROWS && g.size() > 0) {
  + size_t table_ndx = get_next(s) % g.size();
  + TableRef t = g.get_table(table_ndx);
  + if (t->size() > 1) {
  + size_t row_ndx1 = get_next(s) % t->size();
  + size_t row_ndx2 = get_next(s) % t->size();
  + if (row_ndx1 == row_ndx2) {
  + row_ndx2 = (row_ndx2 + 1) % t->size();
  + }
  +
  + if (log) {
  + *log << "g.get_table(" << table_ndx << ")->merge_rows(" << row_ndx1 << ", " << row_ndx2 << ");\n";
  + }
  + t->merge_rows(row_ndx1, row_ndx2);
  + }
  + }
  else if (instr == MOVE_LAST_OVER && g.size() > 0) {
  size_t table_ndx = get_next(s) % g.size();
  TableRef t = g.get_table(table_ndx);
  