Respect the fact that the result object claims it doesn't want to be...

Respect the fact that the result object claims it doesn't want to be interactive by not forwarding STDIN to the python invocation when it isn't desired.

This fixes an issue of running "script" commands via SBDebugger::HandleCommand(...) and SBCommandInterpreter::HandleCommand(...) deadlocking Xcode.

<rdar://problem/18075038>

llvm-svn: 225567