macOS: get page size directly from mach header

[AZero13]

Feature or enhancement

Proposal:

It comes straight from the mach header as a global variable. No need to call to get it.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-142490: for macOS, use vm_page_size directly from the kernel header #142491

[vstinner]

I close the issue since the PR #142491 has been closed.