Pickling an astropy.io.fits.CompImageHDU fails #10512

Description

Attempting to pickle and reload an io.fits.CompImageHDU object produces a TypeError about a missing argument.
This causes failures when using CompImageHDUs with multiprocessing.

Expected behavior

The code below used to successfully recover the hdu object, but now produces the error below.

The configuration I have that is working is:
Linux-5.3.0-51-generic-x86_64-with-debian-buster-sid
Python 3.7.3 (default, Mar 27 2019, 22:11:17)
[GCC 7.3.0]
Numpy 1.16.4
astropy 3.2.1
Scipy 1.3.0
Matplotlib 3.1.1

Actual behavior

TypeError                                 Traceback (most recent call last)
<ipython-input-5-87dc9f19b2d1> in <module>
----> 1 a = pickle.loads(pickle.dumps(hdut))

TypeError: __new__() missing 1 required positional argument: 'table_header'

Steps to Reproduce

import astropy.io.fits as fits
import pickle

hdu = fits.CompImageHDU()
a = pickle.loads(pickle.dumps(hdu))

System Details

Darwin-19.5.0-x86_64-i386-64bit
Python 3.7.6 (default, Jan 8 2020, 13:42:34)
[Clang 4.0.1 (tags/RELEASE_401/final)]
Numpy 1.18.1
astropy 4.0.1.post1
Scipy 1.4.1
Matplotlib 3.1.3

Could also reproduce on:

Linux-5.3.0-51-generic-x86_64-with-debian-buster-sid
Python 3.7.7 (default, May 7 2020, 21:25:33)
[GCC 7.3.0]
Numpy 1.18.1
astropy 4.0.1.post1
Scipy 1.4.1
Matplotlib 3.2.1

and:

Darwin-19.5.0-x86_64-i386-64bit
Python 3.7.6 (default, Jan 8 2020, 13:42:34)
[Clang 4.0.1 (tags/RELEASE_401/final)]
Numpy 1.18.1
astropy 4.2.dev305+ga0f5bbce0
Scipy 1.4.1
Matplotlib 3.1.3

Thanks for reading, glad to provide any other information that would be helpful.