Rollup merge of #112665 - compiler-errors:assumption-takes-clause, r=lcnr

Make assumption functions in new solver take `Binder<'tcx, Clause<'tcx>>`

We just use an if-let to match on an optional clause at all the places where we transition from `Predicate` -> `Clause`, but I assume that when things like item-bounds and param-env start to only store `Clause`s then those can just be trivially dropped.

r? ``@lcnr``

Author: compiler-errors