Improvements to output formatting with the ".trace" command in the
command-line shell.
Make sure the sqlite3_trace() callback is invoked, even if the prepared
statement was marked "expired" before it ever entered sqlite3_step().
Ticket [11d5aa455e0d98f3c1e6a08].
A better fix for the sqlite3_trace() problem.
Ticket [11d5aa455e0d98f3c1e6a]
Modify the memsubsys1-3.1.4 test so that it does not fail arbitrarily due
to variations in the behavior of system malloc().
Minor performance improvement and size reduction for the btree-page space
allocator.