Fix ast error types and messages

Author: youknowone

vm/src/stdlib/ast.rs

@@ -239,7 +239,11 @@ impl Node for ast::Constant {
             }
             builtins::singletons::PyNone => ast::Constant::None,
             builtins::slice::PyEllipsis => ast::Constant::Ellipsis,
-            _ => return Err(vm.new_type_error("unsupported type for constant".to_owned())),
+            obj =>
+                return Err(vm.new_type_error(format!(
+                    "invalid type in Constant: type '{}'",
+                    obj.class().name()
+                ))),
         });
         Ok(constant)
     }

vm/src/stdlib/builtins.rs

@@ -109,6 +109,8 @@ mod builtins {
         dont_inherit: OptionalArg<bool>,
         #[pyarg(any, optional)]
         optimize: OptionalArg<PyIntRef>,
+        #[pyarg(any, optional)]
+        _feature_version: OptionalArg<i32>,
     }
 
     #[cfg(feature = "rustpython-compiler")]
@@ -122,6 +124,10 @@ mod builtins {
         {
             use crate::{class::PyClassImpl, stdlib::ast};
 
+            if args._feature_version.is_present() {
+                eprintln!("TODO: compile() got `_feature_version` but ignored");
+            }
+
             let mode_str = args.mode.as_str();
 
             if args