Auto merge of #96883 - jackh726:early-binder-2, r=oli-obk

Auto merge of #96883 - jackh726:early-binder-2, r=oli-obk

Add EarlyBinder

Chalk has no concept of `Param` (https://github.com/rust-lang/chalk/blob/e0ade19d139bc784384acc6736cd960c91dd55a1/chalk-ir/src/lib.rs#L579) or `ReEarlyBound` (https://github.com/rust-lang/chalk/blob/e0ade19d139bc784384acc6736cd960c91dd55a1/chalk-ir/src/lib.rs#L1308). Everything  is just "bound" - the equivalent of rustc's late-bound. It's not completely clear yet whether to move everything to the same time of binder in rustc or add `Param` and `ReEarlyBound` in Chalk.

Either way, tracking when we have or haven't already substituted out these in rustc can be helpful.

As a first step, I'm just adding a `EarlyBinder` newtype that is required to call `subst`. I also add a couple "transparent" `bound_*` wrappers around a couple query that are often immediately substituted.

r? `@nikomatsakis`