Removed forward declaration of MemBlock class
Removed forward declaration of MemBlock class

Removed forward declaration of MemBlock class.

Declaration is in conflict with declaration `::strings::MemBlock`
google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf,google/protobuf