Rust fixes for v6.9 - Soundness: make internal functions generated by the 'module!' macro inaccessible, do not implement 'Zeroable' for 'Infallible' and require 'Send' for the 'Module' trait. - Build: avoid errors with "empty" files and workaround 'rustdoc' ICE. - Kconfig: depend on '!CFI_CLANG' and avoid selecting 'CONSTRUCTORS'. - Code docs: remove non-existing key from 'module!' macro example. - Docs: trivial rendering fix in arch table.