bugfix Fixnum + Fixnum
Support Inline cache
original commit by miura1729
https://github.com/miura1729/mruby/commit/ed3ef94a4a50946dfe237c27d53375cc4e31ca84
support peephole optimization with inline cache
Support redefine method with inline method cache
original commit by miura1729
https://github.com/miura1729/mruby/commit/7b744897d55b6950189b66afc79b873137fbf74f
Change method cache clear timing for support dynamic undef/alias etc
original commit by miura1729
https://github.com/miura1729/mruby/commit/901f29d79eeb60d2e61aaba17c4254b95e8f32a3
support OP_SEND by C
original commits by miura1729
https://github.com/miura1729/mruby/commit/11ddaef71a4d9b5b8d916729a5abdeb7b48f52bb
https://github.com/miura1729/mruby/commit/a0c060241c00953faab6bf0053308acc633420f4
https://github.com/miura1729/mruby/commit/53e81ee59a11beda3404961597499bb7006ec208
https://github.com/miura1729/mruby/commit/d547eaf9419dc56137bfeed72fc2f91dd5b5e585
https://github.com/miura1729/mruby/commit/295924317398258b0601bd9b07ee0b9389c192d9
Add OP_SENDB