Rollup merge of #142806 - compiler-errors:norm-ct-has-ty, r=lcnr,BoxyUwU

Normalize before computing ConstArgHasType goal in new solver

This is a fix for rust-lang/rust#139905. See the description I left in the test.

I chose to fix this by normalizing the type before matching on its `.kind()` in `compute_const_arg_has_type_goal` (since it feels somewhat consistent with how we normalize types before assembling their candidates, for example); however, there are several other solutions that come to mind for fixing this ICE:
1. (this solution)
2. Giving `ConstKind::Error` a proper type, like `ConstKind::Value`, so that consts don't go from failing to passing `ConstArgHasType` goals after normalization (i.e. `UNEVALUATED` would normalize into a `ConstKind::Error(_, bool)` type rather than losing its type altogether).
3. Just suppressing the errors and accepting the fact that goals can go from fail->pass after normalization.

Thoughts? Happy to discuss this fix further.

r? `@BoxyUwU`

1 files changed, 1 insertions, 0 deletions

diff --git a/compiler/rustc_next_trait_solver/src/solve/mod.rs b/compiler/rustc_next_trait_solver/src/solve/mod.rs
index 4f845ef9cd9..e68ea22c7a2 100644
--- a/compiler/rustc_next_trait_solver/src/solve/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/mod.rs
@@ -191,6 +191,7 @@ where
         goal: Goal<I, (I::Const, I::Ty)>,
     ) -> QueryResult<I> {
         let (ct, ty) = goal.predicate;
+        let ct = self.structurally_normalize_const(goal.param_env, ct)?;
 
         let ct_ty = match ct.kind() {
             ty::ConstKind::Infer(_) => {