Automated g4 rollback of changelist 658524296.

*** Reason for rollback ***

Breaks prototiller TAP

https://fusion2.corp.google.com/triage/-1214429986911055485/7383738244334092288/invocations/6262451a-af31-46f6-9b0a-1e942767980f/targets/%2F%2Fthird_party%2Fprototiller%2Ftransformer:pipeline/history;cell=658524296/08ca1eea-f3db-4c4f-870a-9b231d92e658/log

*** Original change description ***

Add a minimal protoc implementation based on the existing J2ObjC protoc that's used only for generating the class map file, to be used by the eventual J2ObjC proto implementation that will transpile Java proto lite instead of using the custom J2ObjC protoc.

PiperOrigin-RevId: 658598955

Author: j2objc-copybara