…exit}__` (python#118812)

These methods are purely wrappers around `Semlock.{acquire,release}`,
which expect a critical section to be held.

…s for ACLs. (pythonGH-118800)

…ject.c` (python#118850)

…ld (python#118723)

The `list_preallocate_exact` function did not zero initialize array
contents. In the free-threaded build, this could expose uninitialized
memory to concurrent readers between the call to
`list_preallocate_exact` and the filling of the array contents with
items.

…t file (python#118808)

Some embedders and extensions include parts of the internal API. The
pycore_mimalloc.h file is transitively include by a number of other
internal headers. This avoids include errors for code that was
already including those headers.

Avoid immortalizing objects in tests that verify garbage collection of
classes or modules.

This fixes test_ordered_dict and test_struct.

…ython#118722)

Using `race:` filters out warnings if the function appears anywhere in
the stack trace. This can hide a lot of unrelated warnings, especially
for a function like `_PyEval_EvalFrameDefault`, which is somewhere on
the stack more often than not.

Change all free-threaded suppressions to `race_top:`, which only matches
the top frame, and add any new suppressions this exposes.

…ython#118854)

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

…NULL object (python#115433)" (python#118861)

This reverts commit ad4f909.

The API ended up not being used.