Clarify AcqRel's docs

[steveklabnik]

This implied things that are not true.

Fixes #49127

[pietroalbini]

Highfive failed to assign an reviewer, picking someone randomly from the docs team.

r? @frewsxcv

[bors]

@pietroalbini: 🔑 Insufficient privileges: Not in reviewers

[frewsxcv]

@bors r+ rollup

[bors]

📌 Commit deae8de has been approved by frewsxcv

[nagisa]

Well, lets see. The new wording seems as ambiguous to me. One can interpret the new wording as being equivalent to SeqCst in most cases (since Acquire and Release are the two disjoint parts of SeqCst, usually).

Can we just note that this ordering is only applicable for operations that combine both loads and stores and for loads it then uses acquire ordering and for stores it would use the release ordering?

[steveklabnik]

@bors: r-

@nagisa sure, I'll try to hammer that into something. I mostly think that the current wording is very misleading; I'm not particularly attached to my wording here.

[steveklabnik]

r? @nagisa

[nagisa]

@bors r+ rollup

[bors]

📌 Commit 23013c7 has been approved by nagisa