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`

src/tools/compiletest/src/common.rs

@@ -107,7 +107,6 @@ string_enum! {
     #[derive(Clone, Debug, PartialEq)]
     pub enum CompareMode {
         Polonius => "polonius",
-        Chalk => "chalk",
         NextSolver => "next-solver",
         NextSolverCoherence => "next-solver-coherence",
         SplitDwarf => "split-dwarf",

src/tools/compiletest/src/runtest.rs

@@ -2435,9 +2435,6 @@ impl<'test> TestCx<'test> {
             Some(CompareMode::Polonius) => {
                 rustc.args(&["-Zpolonius"]);
             }
-            Some(CompareMode::Chalk) => {
-                rustc.args(&["-Ztrait-solver=chalk"]);
-            }
             Some(CompareMode::NextSolver) => {
                 rustc.args(&["-Ztrait-solver=next"]);
             }

src/tools/tidy/src/deps.rs

@@ -122,10 +122,6 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "byteorder", // via ruzstd in object in thorin-dwp
     "cc",
     "cfg-if",
-    "chalk-derive",
-    "chalk-engine",
-    "chalk-ir",
-    "chalk-solve",
     "compiler_builtins",
     "convert_case", // dependency of derive_more
     "cpufeatures",
@@ -149,7 +145,6 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "fallible-iterator", // dependency of `thorin`
     "fastrand",
     "field-offset",
-    "fixedbitset",
     "flate2",
     "fluent-bundle",
     "fluent-langneg",
@@ -199,7 +194,6 @@ const PERMITTED_RUSTC_DEPENDENCIES: &[&str] = &[
     "parking_lot_core",
     "pathdiff",
     "perf-event-open-sys",
-    "petgraph",
     "pin-project-lite",
     "polonius-engine",
     "ppv-lite86",

src/tools/tidy/src/ui_tests.rs

@@ -11,7 +11,7 @@ use std::path::{Path, PathBuf};
 const ENTRY_LIMIT: usize = 900;
 // FIXME: The following limits should be reduced eventually.
 const ISSUES_ENTRY_LIMIT: usize = 1896;
-const ROOT_ENTRY_LIMIT: usize = 871;
+const ROOT_ENTRY_LIMIT: usize = 870;
 
 const EXPECTED_TEST_FILE_EXTENSIONS: &[&str] = &[
     "rs",     // test source files