Tracking Issue for `static_align` - alignment on static items

This is a tracking issue for a part of RFC "3806" (https://github.com/rust-lang/rfcs/pull/3806).
The feature gate for the issue is #![feature(static_align)].

Related in some ways to fn_align github.com/rust-lang/rust/issues/82232.

#![feature(static_align)]

#[rustc_align_static(64)]
static SO_ALIGNED: u64 = 0;

About tracking issues

Tracking issues are used to record the overall progress of implementation.
They are also used as hubs connecting to other relevant issues, e.g., bugs or open design questions.
A tracking issue is however not meant for large scale discussion, questions, or bug reports about a feature.
Instead, open a dedicated issue for the specific matter and add the relevant feature gate label.
Discussion comments will get marked as off-topic or deleted.
Repeated discussions on the tracking issue may lead to the tracking issue getting locked.

Steps

• Implement the RFC (cc @rust-lang/XXX -- can anyone write up mentoring
  instructions?)
• Adjust documentation (see instructions on rustc-dev-guide)
• Style updates for any new syntax (nightly-style-procedure)
  • Style team decision on new formatting
  • Formatting for new syntax has been added to the Style Guide
  • (non-blocking) Formatting has been implemented in rustfmt
• Stabilization PR (see instructions on rustc-dev-guide)

Unresolved Questions

XXX --- list all the "unresolved questions" found in the RFC to ensure they are
not forgotten

• Should thread_local!s suport alignment in the same way? Are there any platform limitations we'd run into as a result? Initial implementation of thread_local support is in https://github.com/rust-lang/rust/pull/146281.

Implementation history

Start by reading RFC 3806 and the linked tracking issue context for fn_align. Use the checklist to identify the required implementation, documentation, style, and stabilization work, then review the unresolved question about thread_local! alignment. Done means the RFC is implemented, documentation and style work are addressed, and the feature is stabilized.