bpo-40077: Convert mmap to use heap types

[erlend-aasland]

@corona10 or @vstinner, would you mind reviewing this?

https://bugs.python.org/issue40077

[vstinner]

LGTM! This change looks really clean and valid. But I would appreciate another review, just to double check if I missed something.

[vstinner]

cc @shihai1991

[corona10]

lgtm to me also ;)

[shihai1991]

Thanks for your PR. I have no other comments in here.

[erlend-aasland]

Thanks for reviewing, all of you! 🙏🏻

[vstinner]

One less static type! Thanks @erlend-aasland.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot aarch64 RHEL7 3.x has failed when building commit 74b4eda.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/539/builds/282) and take a look at the build logs.
4. Check if the failure is related to this commit (74b4eda) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/539/builds/282

Summary of the results of the build (if available):

== Tests result: ENV CHANGED ==

409 tests OK.

10 slowest tests:

• test_unparse: 4 min 16 sec
• test_concurrent_futures: 4 min 14 sec
• test_tokenize: 3 min 33 sec
• test_capi: 3 min 23 sec
• test_peg_generator: 3 min 7 sec
• test_multiprocessing_spawn: 2 min 55 sec
• test_asyncio: 2 min 20 sec
• test_lib2to3: 2 min 15 sec
• test_unicodedata: 1 min 43 sec
• test_multiprocessing_forkserver: 1 min 37 sec

1 test altered the execution environment:
test_asyncio

14 tests skipped:
test_devpoll test_gdb test_ioctl test_kqueue test_msilib
test_ossaudiodev test_startfile test_tix test_tk test_ttk_guionly
test_winconsoleio test_winreg test_winsound test_zipfile64

Total duration: 7 min 16 sec

Click to see traceback logs

Traceback (most recent call last):
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/sslproto.py", line 321, in __del__
    self.close()
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/sslproto.py", line 316, in close
    self._ssl_protocol._start_shutdown()
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/sslproto.py", line 590, in _start_shutdown
    self._abort()
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/sslproto.py", line 731, in _abort
    self._transport.abort()
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/selector_events.py", line 680, in abort
    self._force_close(None)
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/selector_events.py", line 731, in _force_close
    self._loop.call_soon(self._call_connection_lost, exc)
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/base_events.py", line 746, in call_soon
    self._check_closed()
  File "/home/buildbot/buildarea/3.x.cstratak-RHEL7-aarch64/build/Lib/asyncio/base_events.py", line 510, in _check_closed
    raise RuntimeError('Event loop is closed')
RuntimeError: Event loop is closed