Auto merge of #51037 - pietroalbini:beta-backports, r=pietroalbini
[beta] Process backports
Merged and approved:
* #50812: Fix issue #50811 (`NaN > NaN` was true).
* #50827: Update LLVM to `56c931901cfb85cd6f7ed44c7d7520a8de1edf97`
* #50879: Fix naming conventions for new lints
* #51011: rustdoc: hide macro export statements from docs
r? @ghost