Replace the existing WrapperFunctionResult type in
llvm/include/ExecutionEngine/Orc/Shared/TargetProcessControlTypes.h with a
version adapted from the ORC runtime's implementation.
Also introduce the SimplePackedSerialization scheme (also adapted from the ORC
runtime's implementation) for wrapper functions to avoid manual serialization
and deserialization for calls to runtime functions involving common types.
Lang Hames