Finally, after a lot of hard work from a bunch of people, we're in a state where we can unify LLDB's build system. This patch removes the hand-maintained Xcode project in favor of using CMake in combination with the Xcode generator.
I've included a new script to streamline the process: it creates two build directories in the current directory. The first directory is for LLVM and Clang which uses Ninja to build. The second directory is for LLBD, which configures a standalone build using the Xcode generator.