Auto merge of #74929 - Manishearth:rollup-z2vflrp, r=Manishearth

Rollup of 10 pull requests

Successful merges:

 - #74742 (Remove links to rejected errata 4406 for RFC 4291)
 - #74819 (Point towards `format_spec`; it is in other direction)
 - #74852 (Explain why inlining default ToString impl)
 - #74869 (Make closures and generators a must use types)
 - #74873 (symbol mangling: use ty::print::Print for consts)
 - #74902 (Remove deprecated unstable `{Box,Rc,Arc}::into_raw_non_null` functions)
 - #74904 (Fix some typos in src/librustdoc/clean/auto_trait.rs)
 - #74910 (fence docs: fix example Mutex)
 - #74912 (Fix broken link in unstable book `plugin`)
 - #74927 (Change the target data layout to specify more values)

Failed merges:

r? @ghost