Improve space utilization if we have 3 kB - 8 kB rows to insert in the order of the primary key
btr0cur.c:
  Fix bug: The row count and key cardinality estimate was grossly too small if each clustered index page only contained one record


innobase/btr/btr0cur.c:
  Fix bug: The row count and key cardinality estimate was grossly too small if each clustered index page only contained one record
innobase/btr/btr0btr.c:
  Improve space utilization if we have 3 kB - 8 kB rows to insert in the order of the primary key