of tests are failing with trunk -r869, with this revision using uncompressed
storage, and with this revision hard-wired to use 1-kilobyte compressed pages
and innodb_file_per_table.

btr_push_update_extern_fields(): Do not call ut_ulint_sort() if n_pushed == 0.

btr_copy_externally_stored_field_prefix_low(): Replace ut_max() with ut_min().