Rollup of 7 pull requests#124271

Merged

bors merged 26 commits intorust-lang:masterfrom

GuillaumeGomez:rollup-7st9wd7

Apr 23, 2024

Commits on Apr 19, 2024

Prevent creating the same `Instance::mono` multiple times
GuillaumeGomez
committed

Commits on Apr 20, 2024

Stop taking ParamTy/ParamConst/EarlyParamRegion/AliasTy by ref
compiler-errors
committed

Commits on Apr 22, 2024