Auto merge of #68311 - Dylan-DPC:rollup-wzgqw9t, r=Dylan-DPC

Rollup of 4 pull requests

Successful merges:

 - #66564 (Document unsafe blocks in core::{cell, str, sync})
 - #67791 (Implement Lift using interners instead of in_arena)
 - #68278 ([self-profiler] Add example to `-Z help` to turn on query key recording)
 - #68300 (Allow added string.insert benchmarks to compile)

Failed merges:

r? @ghost