Auto merge of #119023 - compiler-errors:fn-trait-constness, r=fee1-dead

 Check `FnPtr`/`FnDef` built-in fn traits correctly with effects

1. Teach the (old) trait solver how to handle the constness for built-in impls of the `Fn*` family of traits. This unfortunately doesn't support const closures just yet.
2. Fix the `const_eval_select`. It turns out that the `where` clause bounds on `const_eval_select` force the effect parameter for both fndefs to be `true` -- with effects, we will leave off any explicit where clauses and register these obligations manually.

I can elaborate on (2.) if you think it needs a better explanation!

r? fee1-dead

0 files changed, 0 insertions, 0 deletions