Remove all remaining removed_in_20 warnings slated for removal

Finalize all remaining removed-in-2.0 changes so that we
can begin doing pep-484 typing without old things
getting in the way (we will also have to do public_factory).

note there are a few "moved_in_20()" and "became_legacy_in_20()"
warnings still in place.  The SQLALCHEMY_WARN_20 variable
is now removed.

Also removed here are the legacy "in place mutators" for Select
statements, and some keyword-only argument signatures in Core
have been added.

Also in the big change department, the ORM mapper() function
is removed entirely; the Mapper class is otherwise unchanged,
just the public-facing API function.  Mappers are now always
given a registry in which to participate, however the
argument signature of Mapper is not changed. ideally "registry"
would be the first positional argument.

Fixes: #7257

Change-Id: Ic70c57b9f1cf7eb996338af5183b11bdeb3e1623

3 files changed, 10 insertions, 24 deletions

diff --git a/lib/sqlalchemy/testing/assertions.py b/lib/sqlalchemy/testing/assertions.py
index 795b53804..978e6764f 100644
--- a/lib/sqlalchemy/testing/assertions.py
+++ b/lib/sqlalchemy/testing/assertions.py
@@ -31,7 +31,7 @@ from ..util import decorator
 def expect_warnings(*messages, **kw):
     """Context manager which expects one or more warnings.
 
-    With no arguments, squelches all SAWarning and RemovedIn20Warning emitted via
+    With no arguments, squelches all SAWarning emitted via
     sqlalchemy.util.warn and sqlalchemy.util.warn_limited.   Otherwise
     pass string expressions that will match selected warnings via regex;
     all non-matching warnings are sent through.
@@ -41,9 +41,7 @@ def expect_warnings(*messages, **kw):
     Note that the test suite sets SAWarning warnings to raise exceptions.
 
     """  # noqa
-    return _expect_warnings(
-        (sa_exc.RemovedIn20Warning, sa_exc.SAWarning), messages, **kw
-    )
+    return _expect_warnings(sa_exc.SAWarning, messages, **kw)
 
 
 @contextlib.contextmanager
@@ -199,9 +197,7 @@ def _expect_warnings(
             else:
                 real_warn(msg, *arg, **kw)
 
-        with mock.patch("warnings.warn", our_warn), mock.patch(
-            "sqlalchemy.util.SQLALCHEMY_WARN_20", True
-        ), mock.patch("sqlalchemy.util.deprecations.SQLALCHEMY_WARN_20", True):
+        with mock.patch("warnings.warn", our_warn):
             try:
                 yield
             finally:
diff --git a/lib/sqlalchemy/testing/profiling.py b/lib/sqlalchemy/testing/profiling.py
index 2761d4987..6ccfe4ea7 100644
--- a/lib/sqlalchemy/testing/profiling.py
+++ b/lib/sqlalchemy/testing/profiling.py
@@ -238,21 +238,18 @@ def function_call_count(variance=0.05, times=1, warmup=0):
     # likely due to the introduction of __signature__.
 
     from sqlalchemy.util import decorator
-    from sqlalchemy.util import deprecations
-    from sqlalchemy.testing import mock
 
     @decorator
     def wrap(fn, *args, **kw):
 
-        with mock.patch.object(deprecations, "SQLALCHEMY_WARN_20", False):
-            for warm in range(warmup):
-                fn(*args, **kw)
+        for warm in range(warmup):
+            fn(*args, **kw)
 
-            timerange = range(times)
-            with count_functions(variance=variance):
-                for time in timerange:
-                    rv = fn(*args, **kw)
-                return rv
+        timerange = range(times)
+        with count_functions(variance=variance):
+            for time in timerange:
+                rv = fn(*args, **kw)
+            return rv
 
     return wrap
 
diff --git a/lib/sqlalchemy/testing/warnings.py b/lib/sqlalchemy/testing/warnings.py
index c8e481a90..0c550731c 100644
--- a/lib/sqlalchemy/testing/warnings.py
+++ b/lib/sqlalchemy/testing/warnings.py
@@ -46,13 +46,6 @@ def setup_filters():
         message="The loop argument is deprecated",
     )
 
-    # ignore things that are deprecated *as of* 2.0 :)
-    warnings.filterwarnings(
-        "ignore",
-        category=sa_exc.SADeprecationWarning,
-        message=r".*\(deprecated since: 2.0\)$",
-    )
-
     try:
         import pytest
     except ImportError: