Auto merge of #113303 - compiler-errors:yeet-chalk, r=lcnr

Remove chalk support from the compiler

Removes chalk (`-Ztrait-solver=chalk`) from the compiler and prunes any dead code resulting from this, mainly:
* Remove the chalk compatibility layer in `compiler/rustc_traits/src/chalk`
* Remove the chalk flag `-Ztrait-solver=chalk` and its `TraitEngine` implementation
* Remove `TypeWellFormedFromEnv` (and its many `bug!()` match arms)
* Remove the chalk migration mode from compiletest
* Remove the `chalkify` UI tests (do we want to keep any of these, but migrate them to `-Ztrait-solver=next`??)

Fulfills rust-lang/types-team#93.

r? `@jackh726`

1 files changed, 1 insertions, 2 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 19dd4ce06b0..61f693e1bd1 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -1,8 +1,8 @@
 use std::cell::RefCell;
 use std::fmt::Debug;
 
+use super::FulfillmentContext;
 use super::TraitEngine;
-use super::{ChalkFulfillmentContext, FulfillmentContext};
 use crate::solve::FulfillmentCtxt as NextFulfillmentCtxt;
 use crate::traits::error_reporting::TypeErrCtxtExt;
 use crate::traits::NormalizeExt;
@@ -39,7 +39,6 @@ impl<'tcx> TraitEngineExt<'tcx> for dyn TraitEngine<'tcx> {
             (TraitSolver::Next | TraitSolver::NextCoherence, true) => {
                 Box::new(NextFulfillmentCtxt::new(infcx))
             }
-            (TraitSolver::Chalk, false) => Box::new(ChalkFulfillmentContext::new(infcx)),
             _ => bug!(
                 "incompatible combination of -Ztrait-solver flag ({:?}) and InferCtxt::next_trait_solver ({:?})",
                 infcx.tcx.sess.opts.unstable_opts.trait_solver,