RUBY_FL_EXIVAR   1235 include/ruby/ruby.h #define FL_EXIVAR       RUBY_FL_EXIVAR
RUBY_FL_EXIVAR   2010 include/ruby/ruby.h     if (RB_FL_TEST(obj, RUBY_FL_EXIVAR)) rb_copy_generic_ivar(clone, obj);
RUBY_FL_EXIVAR   2017 include/ruby/ruby.h     if (RB_FL_TEST(obj, RUBY_FL_EXIVAR)) rb_copy_generic_ivar(dup, obj);