Fixed functions to always reply to packets and added a port offset.

Fixed a bunch of issues with many functions that were added for the platform host IO calls where they might not reply to the packet if the packet was malformed.

Cleaned up error codes.

Added a port offset to allow for connections across a USB mux.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@195485 91177308-0d34-0410-b5e6-96231b3b80d8