Change ProcessGDBRemote::DidLaunchOrAttach to 
call Target::SetArchitecture instead of modifying a
reference to the target's architecture so that the
target logging can show that the arch has been changed.


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@214667 91177308-0d34-0410-b5e6-96231b3b80d8