Support compare instructions
original commit by miura1729
https://github.com/miura1729/mruby/commit/3a7f6f19326c6e505ca53a4e210fe324e89e8edb
Support compare instructions for float object
original commit by miura1729
https://github.com/miura1729/mruby/commit/48276debf6b4cdc844d96f3693eaaf9b59545b73
Add jmpif/jmpnot instructions
original commit by miura1729
https://github.com/miura1729/mruby/commit/0040a5e4eebf69659d44c66a9a2c2d4c4fc5cd82
fix addi() to use not overflowed number
original commit by miura1729
https://github.com/miura1729/mruby/commit/0040a5e4eebf69659d44c66a9a2c2d4c4fc5cd82
Code space is only one
original commit by miura1729
https://github.com/miura1729/mruby/commit/d20994429cb7c00398684c11db501b952a9aaf29
Support OP_NOP
original commit by miura1729
https://github.com/miura1729/mruby/commit/892eab5cd7e1688311ce1f29e7b5665253c47d45
update xtaak