Rollup merge of #142126 - compiler-errors:normalize-uv-via-relate, r=BoxyUwU

Treat normalizing consts like normalizing types in deeply normalize

...so that we don't end up putting a top-level normalizes-to goal in the fulfillment context, which ICEs. This basically just models the normalize-const code off of the normalize-ty code above it, which uses an alias-relate goal instead.

Fixes rust-lang/rust#140571

r? lcnr

Author: GuillaumeGomez