mesonbuild
Skip symlinks in _make_tree_writable()
Trying to chmod a symlink results in trying to chmod the file or directory it points to, not the symlink itself which has no permissions. Either a symlink points to within the tree we're making writable in which case it'll be handled eventually by os.walk() or it points outside of the tree we're making writable in which case we don't want to touch it. Let's avoid touching files outside of the tree by simply skipping symlinks in _make_tree_writable().
@dcbaker @bonzini Any chance you could take a quick look? Trivial fix for a rather annoying issue
@bonzini I can press merge if you think this is the right approach (since you've already looked at it more than I have)
