Auto merge of #139577 - davidtwco:sizedness-go-vroom, r=oli-obk

re-use `Sized` fast-path

There's an existing fast path for the `type_op_prove_predicate` predicate, checking for trivially `Sized` types, which can be re-used when evaluating obligations within queries. This should improve performance and was found to be beneficial in #137944.

r? types

Author: bors