Tracking Issue for c-char-type

This is a tracking issue for the -Zc-char-type='unsigned|signed|default' (configurable c_char override to i8/u8).
The feature gate for the issue is #![feature(c_char_type)].

Requested by Rust-For-Linux as gcc/clang -funsigned-char analog: https://github.com/Rust-for-linux/linux/issues/355.

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

• Implementation PR: https://github.com/rust-lang/rust/pull/138290
• Adjust documentation (see instructions on rustc-dev-guide)
• Formatting for new syntax has been added to the Style Guide (nightly-style-procedure)
• Stabilization PR (see instructions on rustc-dev-guide)

Unresolved Questions

Implementation history

Implementation PR: https://github.com/rust-lang/rust/pull/138290

Start with implementation PR 138290, then read the rustc-dev-guide stabilization and documentation instructions linked in the issue. Check the Style Guide and nightly-style procedure for the required formatting work. Done means the implementation, documentation, formatting, and stabilization checklist items are complete.