regression: HashMap/Set::from inference failures

[Mark-Simulacrum]

• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/gh/ImGabe.good-morning-api/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/gh/ahogappa0613.spexm/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/gh/alexanderbladyko.caverna_bot/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/gh/fifth-postulate.double-memory/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/gh/jcrowgey.aoc_2019/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/gh/martskins.aoc2020/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/gh/ocstl.advent_of_code_2015/log.txt
• https://crater-reports.s3.amazonaws.com/beta-1.56-2/beta-2021-09-12/reg/trenitalia-0.3.4/log.txt

Likely caused by https://github.com/rust-lang/rust/pull/84111, don't think this was discussed as part of that. Likely acceptable breakage -- just inference regressions, not too many cases.

[m-ou-se]

Discussed in the libs-api meeting. Closing as acceptable, as the impact is small.