Co-Authored-By: Ralf Jung <post@ralfj.de>

Also add the `default` option so that it's easy to add query key
recording to the default.

…l-str, r=Amanieu

Document unsafe blocks in core::{cell, str, sync}

Split from rust-lang#66506 (issue rust-lang#66219). Hopefully doing a chunk at a time is more manageable!

r? @RalfJung

Implement Lift using interners instead of in_arena

r? @eddyb
cc @cjgillot

…xcrichton

Fix CI for embedded ARM targets

Closes rust-lang#67018

It would be better to move the `thumb-none-cortex-m` test into the `cargotest` suite, but it doesn't seem to support cross-compilation.

…, r=michaelwoerister

[self-profiler] Add example to `-Z help` to turn on query key recording

Also add the `default` option so that it's easy to add query key
recording to the default.

r? @michaelwoerister

Allow added string.insert benchmarks to compile

Allow the code added by rust-lang#67281 to compile.

(symptons listed [in internals forum](https://internals.rust-lang.org/t/x-py-how-to-benchmark-liballoc/11635))
r? @llogiq