vm_eval.c: cache results
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51665 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
vm_eval.c: cache results
results of respond_to? and respond_to_missing?, and search a
pulibc method only for compatibility with rb_respond_to.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51665 b2dd03c8-39d4-4d8f-98ff-823fe69b080e