Auto merge of #140079 - ChrisDenton:rollup-2h5cg94, r=ChrisDenton

Rollup of 5 pull requests

Successful merges:

 - #137953 (simd intrinsics with mask: accept unsigned integer masks, and fix some of the errors)
 - #139990 (transmutability: remove NFA intermediate representation)
 - #140044 (rustc-dev-guide subtree update)
 - #140051 (Switch exploit mitigations to mdbook footnotes)
 - #140054 (docs: fix typo change from inconstants to invariants)

r? `@ghost`
`@rustbot` modify labels: rollup