[discussion] compatible with two cases about krotodc

[mscheong01]

Hi, thanks for the detailed explanations!

1. oneof names
   I'm aware with issues that can arise from oneof names, which was also reported in #4. However, I'm still considering whether these cases should be handled. As you mentioned, this kind of proto definitions are against the basic conventions and will not likely be used. If we decide to take care of this, I think the solution will be to change the oneof sealed class names to ~Oneof (although it is breaking change)
2. special field name like xx_2nd -> I was not aware of this issue. I'll look into your PR soon!

[blackhuman]

Regarding point 1, while it is certainly a significant matter, I cannot recall any instances where the oneof field name generated by protobuf-java was directly referenced in actual code. From what I understand, the existence of the 'tagCode' field (as seen in the example above) is primarily intended to ensure successful compilation. Since my knowledge of protobuf is limited, I cannot say for certain whether this implementation would disrupt existing code.