Remove ptr from AtomicPtr::fetch_{add,sub} method names

[WaffleLapkin]

Rename AtomicPtr::{fetch_ptr_add => fetch_add, fetch_ptr_sub => fetch_sub}.

Reasoning TL;DR: new naming is consistent with other Atomic* and pointer methods, see #99108 (comment)

r? @thomcc

[rustbot]

The Miri subtree was changed

cc @rust-lang/miri

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[WaffleLapkin]

@rustbot label +T-libs-api -T-libs

[thomcc]

I agree this naming as-is is not ideal, but it was done deliberately to avoid the footgun described here: #96935 (comment). That is, the initial version of the PR used the names you describe and was changed to avoid confusion.

[thomcc]

That said I am in favor of changing the name. I think fetch_ptr_add implies it's in units of size_of::<*const T>() rather than size_of::<T>().

[thomcc]

Do you want to open an ACP about this as a place to hold the bikeshed coloring discussion?

[WaffleLapkin]

Yeah, I think it's a good idea

[WaffleLapkin]

Opened ACP: rust-lang/libs-team#126

[WaffleLapkin]

ACP was declined