Write back to class

[Ran-Mewo]

Hi! I just want to how to write it back into bytecode, thanks!

[zsqw123]

• struct ClassFile already implemented WriteInto, it should be write to bytecode easily, but I'm now sure, you can test it, if any issues meet, tell me pls, thx.
• we only support jvms write back, node related api not implemented yet, thanks for contributing :)