Fix class/instance variable name validation

- `@@?` etc are invalid class variable name.
- `@1` etc are invalid instance variable name.

1 files changed, 3 insertions, 4 deletions

diff --git a/test/t/kernel.rb b/test/t/kernel.rb
index 74176fbd0..d99358c0c 100644
--- a/test/t/kernel.rb
+++ b/test/t/kernel.rb
@@ -391,11 +391,10 @@ assert('Kernel#remove_instance_variable', '15.3.1.3.41') do
 
   tri = Test4RemoveInstanceVar.new
   assert_equal 99, tri.var
-  tri.remove
+  assert_equal 99, tri.remove
   assert_equal nil, tri.var
-  assert_raise NameError do
-    tri.remove
-  end
+  assert_raise(NameError) { tri.remove }
+  assert_raise(NameError) { tri.remove_instance_variable(:var) }
 end
 
 # Kernel#require is defined in mruby-require. '15.3.1.3.42'