Rollup of 5 pull requests#91287

Closed

matthiaskrgr wants to merge 13 commits intorust-lang:masterfrom

matthiaskrgr:rollup-l8vgj0l

Commits on Aug 11, 2021

Weaken guarantee around advancing underlying iterators in zip
the8472
committed

Commits on Nov 18, 2021

Document non-guarantees for Hash
the8472
committed

Commits on Nov 19, 2021

Expand available_parallelism docs in anticipation of cgroup quotas
the8472
committed

Commits on Nov 23, 2021

Apply suggestions from code review

the8472
and
pierwill
authored

Commits on Nov 25, 2021

Commits on Nov 26, 2021

Only check for errors in predicate when skipping impl assembly
Aaron1011
committed