Fixed Xcode project after recent changes:

"After recent changes, some code has become redundant. This revision tries to remove
the un-used code and tidy up the rest.

Following 4 files have been removed. I have updated CMake files and checked that it builds
fine on Linux and Windows. Can somebody update the xcode related file accordingly?

tools/lldb-mi/MICmnStreamStdinLinux.cpp
tools/lldb-mi/MICmnStreamStdinLinux.h
tools/lldb-mi/MICmnStreamStdinWindows.cpp
tools/lldb-mi/MICmnStreamStdinWindows.h"

llvm-svn: 230401