to protect against unknown conditions when splicing inner joins
together within joined eager loads with ``innerjoin=True``; if
some of the joins use a "secondary" table, the assertion needs to
unwrap further joins in order to pass.
fixes #3412

between fully and match on those, rather than trying to
compare selectables; fixes #3347

exists in 0.9 as well but is more of a regression in 1.0 due to
:ticket:`3008` which turns on "nested" by default, such that
a joined eager load that travels across sibling paths from a common
ancestor using innerjoin=True will correctly splice each "innerjoin"
sibling into the appropriate part of the join, when a series of
inner/outer joins are mixed together.
fixes #3347

is used with a one-to-many query that also features LIMIT,
OFFSET, or DISTINCT has been disabled in the case of a one-to-one
relationship, that is a one-to-many with
:paramref:`.relationship.uselist` set to False.  This will produce
more efficient queries in these cases.
fixes #3249

a much more modest outcome than what we started with.   The
work of create_row_processor() for ColumnProperty objects
is essentially done at query setup time combined with some
lookups in _instance_processor().
- to allow this change for deferred columns, deferred columns
no longer search for themselves in the result.   If they've been
set up as deferred without any explicit directive to undefer them,
then this is what was asked for.  if we don't do this,
then we're stuck with this performance penalty for all deferred
columns which in the vast majority of typical use cases (e.g. loading
large, legacy tables or tables with many/large very seldom
used values) won't be present in the result and won't be accessed at all.

be contributing to pypy not cleaning up on this one