bpo-42217: compiler: merge same co_code and co_linetable objects

[methane]

Make the compiler merges co_code and co_lnotab in a module, like already done for co_consts.

https://bugs.python.org/issue42217

[github-actions]

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[merwok]

Suggested change

	Make the compiler merges co_code and co_lnotab in a module.
	Make the compiler merge module attributes co_code and co_lnotab.

[methane]

It is not module attributes.

There are many code objects in module. All code modules have co_code and co_lnotab that are bytes objects.
Since bytes objects are immutables, same objects can be shared.

[methane]

How about "Make the compiler merges same co_code and co_linetable objects in a module like already did for co_consts."

[merwok]

Ah, then I don’t understand this well enough (the PR or the suggested text) to say 😐

When you pick a phrasing, I think it will be necessary to update the PR title so that the resulting squashed commit is correct + fix the extra s (should be make compiler merge, not merges).

[pfalcon]

Make the compiler merges co_code and co_lnotab

When I read this, I imagine that .co_code and .co_lnotab will now point to the same bytes object.