Stabilize waker_getters

[oxalica]

Close #96992
Close #87021

API summary:

// core::task
impl RawWaker {
    pub fn data(&self) -> *const ();
    pub fn vtable(&self) -> &'static RawWakerVTable;
}
impl Waker {
    pub fn as_raw(&self) -> &RawWaker;
}

[rustbot]

Hey! It looks like you've submitted a new PR for the library teams!

If this PR contains changes to any rust-lang/rust public library APIs then please comment with @rustbot label +T-libs-api -T-libs to tag it appropriately. If this PR contains changes to any unstable APIs please edit the PR description to add a link to the relevant API Change Proposal or create one if you haven't already. If you're unsure where your change falls no worries, just leave it as is and the reviewer will take a look and make a decision to forward on if necessary.

Examples of T-libs-api changes:

• Stabilizing library features
• Introducing insta-stable changes such as new implementations of existing stable traits on existing stable types
• Introducing new or changing existing unstable library APIs (excluding permanently unstable features / features without a tracking issue)
• Changing public documentation in ways that create new stability guarantees
• Changing observable runtime behavior of library APIs

[rust-highfive]

r? @m-ou-se

(rust-highfive has picked a reviewer for you, use r? to override)

[oxalica]

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

[TiddoLangerak]

Has there been any progress on this recently? When could we expect this to land in stable?

[oxalica]

Has there been any progress on this recently? When could we expect this to land in stable?

I'm not familiar with the formal stabilization steps. Seems we need an FCP.
r? rust-lang/libs-api

[Amanieu]

I raised a concern about the API in the tracking issue: #96992 (comment)

[Dylan-DPC]

@oxalica any updates on this?

[Dylan-DPC]

Closing this as some concerns (listed on the tracking issue) still need to be resolved before we stabilise this so it's going to be a while.