Rollup merge of #152478 - bjorn3:lto_refactors10, r=wesleywiser

Remove tm_factory field from CodegenContext

This is necessary to support serializing the `CodegenContext` to a `.rlink` file in the future for moving LTO to the `-Zlink-only` step.

Follow up to https://github.com/rust-lang/rust/pull/149209
Part of https://github.com/rust-lang/compiler-team/issues/908