Final patch
-----------
This WL is about using this bitmap in all parts of the partition handler.
Thus for:
rnd_init/rnd_next
index_init/index_next and all other variants of index scans
read_range_... the various range scans implemented in the partition handler.
Also use those bitmaps in the various other calls that currently loop over all
partitions.
- post-...-post review fixes
- Added "integer range walking" that allows to do partition pruning for "a <=? t.field <=? b"
by finding used partitions for a, a+1, a+2, ..., b-1, b.
- Added more comments.
- Added a RANGE_OPT_PARAM::remove_jump_scans flag that disables construction of index_merge
SEL_TREEs that represent unusable conditions like "key1part1<c1 OR key2part2<c2"
- make prune_partitions() function handle the case where range analysis produces a list of
index_merge trees (it turned out that this is possible, appropriate test case added).
- Other small fixes.
