Add Param ty to SMIR

compiler/rustc_smir/src/rustc_smir/mod.rs

@@ -825,7 +825,7 @@ fn stable(&self, tables: &mut Tables<'tcx>) -> Self::T {
             ty::Alias(alias_kind, alias_ty) => {
                 TyKind::Alias(alias_kind.stable(tables), alias_ty.stable(tables))
             }
-            ty::Param(_) => todo!(),
+            ty::Param(param_ty) => TyKind::Param(param_ty.stable(tables)),
             ty::Bound(_, _) => todo!(),
             ty::Placeholder(..)
             | ty::GeneratorWitness(_)
@@ -837,3 +837,11 @@ fn stable(&self, tables: &mut Tables<'tcx>) -> Self::T {
         }
     }
 }
+
+impl<'tcx> Stable<'tcx> for rustc_middle::ty::ParamTy {
+    type T = stable_mir::ty::ParamTy;
+    fn stable(&self, _: &mut Tables<'tcx>) -> Self::T {
+        use stable_mir::ty::ParamTy;
+        ParamTy { index: self.index, name: self.name.to_string() }
+    }
+}

compiler/rustc_smir/src/stable_mir/ty.rs

@@ -18,6 +18,7 @@ pub fn kind(&self) -> TyKind {
 pub enum TyKind {
     RigidTy(RigidTy),
     Alias(AliasKind, AliasTy),
+    Param(ParamTy),
 }
 
 #[derive(Clone, Debug)]
@@ -228,3 +229,9 @@ pub struct ExistentialProjection {
     pub generic_args: GenericArgs,
     pub term: TermKind,
 }
+
+#[derive(Clone, Debug)]
+pub struct ParamTy {
+    pub index: u32,
+    pub name: String,
+}