be properly typed as boolean in the result, and also would fail to be
anonymously aliased in a SELECT list as is the case with a
non-negated EXISTS construct.
fixes #3682

(cherry picked from commit 07a4b6cbcda6e6ee6e67893c5a5d2fd01e5f125f)

for ref #3657.  The Oracle dialect makes more use of the "select_wraps_for"
feature than SQL server because Oracle doesn't have "TOP" for a limit-only
select, so tests are showing more happening here.  In the case where
the select() has some dupe columns, these are deduped from the .c collection
so a positional match between the wrapper and original can't use .inner_columns,
because these collections wont match.  Using _columns_plus_names
instead which is the deduped collection that determines the SELECT display,
which definitely have to match up.

handled within visit_select(); this attribute was added in the
1.0 series to accommodate the subquery wrapping behavior of
SQL Server and Oracle while also working with positional
column targeting and no longer relying upon "key fallback"
in order to target columns in such a statement.  The IBM DB2
third-party dialect also has this use case, but its implementation
is using regular expressions to rewrite the textual SELECT only
and does not make use of a "wrapped" select at this time.
The logic no longer attempts to reconcile proxy set collections as
this was not deterministic, and instead assumes that the select()
and the wrapper select() match their columns postionally,
at least for the column positions they have in common,
so it is now very simple and safe.  fixes #3657.
- as a side effect of #3657 it was also revealed that the
strategy of calling upon a ResultProxy._getter was not
correctly calling into NoSuchColumnError when an expected
column was not present, and instead returned None up to
loading.instances() to produce NoneType failures; added
a raiseerr argument to _getter() which is called when we
aren't expecting None, fixes #3658.

(cherry picked from commit 8ad968f33100baeb3b13c7e0b724b6b79ab4277f)

present in the commit for master, having been inadvertently committed
on February 3.  Source of this line is c1316a299257fae8264c8038d83e415f4605fde7.

- move tests to CRUDTest
- changelog, fixes #3643

(cherry picked from commit 150591f9e0a94902cb2a76b68ac7c9d8a1a3ec83)

(cherry picked from commit c9b03fa8afd52646aba8c59fc038330eeee6db60)

(cherry picked from commit 859379e2fcc4506d036700ba1eca4c0ae526a8ee)

no longer called for an UPDATE or DELETE statement emitted via plain
text or via the :func:`.text` construct, affecting those drivers
that erase cursor.rowcount once the cursor is closed such as SQL
Server ODBC and Firebird drivers.
fixes #3622

(cherry picked from commit 197ffa2be2cadce3df8bfb0799b3c80158250286)

such as a CHECK constraint would render an erroneous comma in the
definition; this scenario can occur such as with a Postgresql
INHERITS table that has no columns of its own.
fixes #3598

(cherry picked from commit 9695faf32981406b12a6468b98d5c9b673f8e219)

For example, this query:

    SELECT s1.users.name FROM s1.users FOR UPDATE OF s1.users

should actually be:

    SELECT s1.users.name FROM s1.users FOR UPDATE OF users

fixes #3573

(cherry picked from commit fd47fea6fbb11ee84b7eea5772f40855703ebe47)