These just copy commands from Products/Release/. But with #52256 we
now build .dsym directories that somehow wind up in Products/Release/.
This makes things more exact by just copying the files in Products/Release/.
Not every package that needs xcbuild will want to use its build phase.
I have moved the xcbuild setup hook to the new attribute xcbuildHook.
This means that dontUseXcbuild is no longer needed. If you just need
to call xcbuild on its own you can just refer to xcbuild.
