Added a new stable API function ``PyType_FromMetaclass``, which mirrors
the behavior of ``PyType_FromModuleAndSpec`` except that it takes an
additional metaclass argument. This is, e.g., useful for language
binding tools that need to store additional information in the type
object.
Remove the PyUnicode_InternImmortal() function and the
SSTATE_INTERNED_IMMORTAL macro.
The PyUnicode_InternImmortal() function is still exported in the
stable ABI. The function is removed from the API.
PyASCIIObject.state.interned size is now a single bit, rather than 2
bits.
Keep SSTATE_NOT_INTERNED and SSTATE_INTERNED_MORTAL macros for
backward compatibility, but no longer use them internally since the
interned member is now a single bit and so can only have two values
(interned or not interned).
Update stats of _PyUnicode_ClearInterned().
Petr Viktorin
Wenzel Jakob
Victor Stinner
Inada Naoki