Emit error instead of delayed bug when meeting mismatch type for const tuple

Author: mu001999

compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs

@@ -2502,11 +2502,12 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         let tcx = self.tcx();
 
         let FeedConstTy::WithTy(ty) = feed else {
-            return Const::new_error_with_message(tcx, span, "unsupported const tuple");
+            return Const::new_error_with_message(tcx, span, "const tuple lack type information");
         };
 
         let ty::Tuple(tys) = ty.kind() else {
-            return Const::new_error_with_message(tcx, span, "const tuple must have a tuple type");
+            let e = tcx.dcx().span_err(span, format!("expected {}, found const tuple", ty));
+            return Const::new_error(tcx, e);
         };
 
         let exprs = exprs

tests/ui/const-generics/mgca/tuple_expr_arg_mismatch_type.rs

@@ -0,0 +1,8 @@
+#![feature(min_generic_const_args)]
+#![expect(incomplete_features)]
+
+pub fn takes_nested_tuple<const N: u32>() {
+    takes_nested_tuple::<{ () }> //~ ERROR expected u32, found const tuple
+}
+
+fn main() {}

tests/ui/const-generics/mgca/tuple_expr_arg_mismatch_type.stderr

@@ -0,0 +1,8 @@
+error: expected u32, found const tuple
+  --> $DIR/tuple_expr_arg_mismatch_type.rs:5:28
+   |
+LL |     takes_nested_tuple::<{ () }>
+   |                            ^^
+
+error: aborting due to 1 previous error
+