Fix another old usage of GetCurrentThread() to get a mach port
number in RNBRemote::HandlePacket_qProcessInfo -- add a new
GetCurrentThreadMachPort() so callers who need to make a mach
thred_get_state() call at the RNBRemote level will have a way to
get the port number.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@178619 91177308-0d34-0410-b5e6-96231b3b80d8