vm.c: hide singleton class of frozen-core

* vm.c (Init_VM): hide also the singleton class of frozen-core, not
  only frozen-core itself.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43232 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 3 insertions, 0 deletions

diff --git a/vm.c b/vm.c
index a43f3d6b20..0ade176c42 100644
--- a/vm.c
+++ b/vm.c
@@ -2285,6 +2285,9 @@ Init_VM(void)
     rb_define_method_id(klass, idProc, rb_block_proc, 0);
     rb_define_method_id(klass, idLambda, rb_block_lambda, 0);
     rb_obj_freeze(fcore);
+    RBASIC_CLEAR_CLASS(klass);
+    RCLASS_SET_SUPER(klass, 0);
+    rb_obj_freeze(klass);
     rb_gc_register_mark_object(fcore);
     rb_mRubyVMFrozenCore = fcore;