Add ProcessGDBRemote::GetAuxvData() and fix multiple-packet concatenation for binary data.

ProcessGDBRemote::GetAuxvData obtains the auxv from a remote gdbserver (via a binary-data packet), and returns the data as a DataBufferSP.

The patch includes a small fix to GDBRemoteCommunicationClient::SendPacketsAndConcatenateResponses() to support binary file format packet returns (by not assuming each binary packet is a null-terminated string when concatenating them).



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@202907 91177308-0d34-0410-b5e6-96231b3b80d8