Xcode llvm+clang build and errors on first build of llvm-build

Hey all,

The first time an Xcode build creates the llvm-build structure, it does some directory-making commands that are marked as failing. Xcode builds anyway and doesn’t treat them as show-stoppers on the IDE build. However, when we build that first build from the command line with the Xcode command-line tools, that does trigger an exit code that looks like the build fails.

I’d love it if we fix up the llvm+clang build portion of the Xcode build to just not report those as failures since they don’t even look like semantic failures. On the surface it looks as simple as making sure we either use a ‘-p’ with a mkdir or a Makefile “ignore the result” command execute option for making the relevant dirs.

Apple folks - do you care if we poke at that llvm+clang build code/build script and fix that?