bpo-36332: Allow compile() to handle AST objects with assignment expressions (GH-12398)


diff --git a/Python/ast.c b/Python/ast.c
index 971b8dd..e9154fe 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -316,13 +316,14 @@
         return validate_exprs(exp->v.List.elts, ctx, 0);
     case Tuple_kind:
         return validate_exprs(exp->v.Tuple.elts, ctx, 0);
+    case NamedExpr_kind:
+        return validate_expr(exp->v.NamedExpr.value, Load);
     /* This last case doesn't have any checking. */
     case Name_kind:
         return 1;
-    default:
-        PyErr_SetString(PyExc_SystemError, "unexpected expression");
-        return 0;
     }
+    PyErr_SetString(PyExc_SystemError, "unexpected expression");
+    return 0;
 }
 
 static int