Add an experimental fix to avoid attempting to mmap memory from an offset that is not a multiple of the system page size on systems with page sizes larger than 32KB.
Add a test to ensure os_unix.c works with 64KiB OS pages.
Avoid attempting to mmap memory from an offset that is not a multiple of the system page size on systems with page sizes larger than 32KB.
Fix arithmetic operators so that they do not change the affinity of their
input operands.  Ticket [a8a0d2996a].
Remove unused variables Parse.nColCache and Parse.iColCache.
Detect when a VdbeCursor is still pointing at a valid row but that row has
moved, and invalidated the return from prior sqlite3BtreeDataFetch() or
sqlite3BtreeKeyFetch() calls.
Add an ORDER BY test case to speedtest1.c
Remove the sequence values from sorter records used by ORDER BY as well.
Fix a problem in the code added by [707ea170b3] causing vdbesort.c to sort unstably.
Add another performance test case to speedtest1.  This case is another
ORDER BY test but this time without LIMIT.
Merge enhancements and fixes from trunk.