Auto merge of #77954 - JohnTitor:rollup-bpoy497, r=JohnTitor

Rollup of 9 pull requests

Successful merges:

 - #77570 (Allow ascii whitespace char for doc aliases )
 - #77739 (Remove unused code)
 - #77753 (Check html comments)
 - #77879 (Provide better documentation and help messages for x.py setup)
 - #77902 (Include aarch64-pc-windows-msvc in the dist manifests)
 - #77934 (Document -Z codegen-backend in the unstable book)
 - #77936 (Remove needless alloc_slice)
 - #77946 (Validate references to source scopes)
 - #77951 (Update books)

Failed merges:

r? `@ghost`