Auto merge of #117513 - matthiaskrgr:rollup-jvl6y84, r=matthiaskrgr

Rollup of 4 pull requests

Successful merges:

 - #117394 (use global cache when computing proof trees)
 - #117495 (Clarify `Unsize` documentation)
 - #117509 (Remove support for alias `-Z symbol-mangling-version`)
 - #117512 (Expand mem::offset_of! docs)

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