Protobuf: protoc: allow using stdin/stdout in FILE/FILES parameters

[mvdan]

For example, right now I'm doing:

protoc -o/dev/stdout --include_imports test.proto

I am calling protoc from a Go program, so this limitation requires me to either use a temporary file, or hard-code /dev/stdout which is not portable. Both are unnecessarily complex.

I'm not sure what the best way to expose this would be. Some programs use special values, such as - to mean standard input.

[foisonocean]

Any updates?