publics/golang__protobuf @ api-v2

Joe Tsai 945a1706d0 all: rely on message_set_extension name mangling in ExtensionDescV1		5 lat temu
..
conformance.pb.go	abd06a8b30 all: update to protobuf-v3.9.1 and go-v1.11.13 and go-v1.12.9	5 lat temu
test_messages_proto2.pb.go	945a1706d0 all: rely on message_set_extension name mangling in ExtensionDescV1	5 lat temu
test_messages_proto3.pb.go	7328839f81 cmd/protoc-gen-go: annotate depIdxs list with index comments	5 lat temu