737b461555
implement deep normalization via the new solver together with #112869 this should remove all uses of the old solver with `-Ztrait-solver=next`. see https://hackmd.io/V0qsUB_fTxexfQO_pcOcrg for a description of this PR. Will move that doc to the `rustc-dev-guide` after merging this. r? `@compiler-errors`