As discussed on llvm-dev in http://lists.llvm.org/pipermail/llvm-dev/2017-September/117301.html this changes the command line interface of llvm-dwarfdump to match the one used by the dwarfdump utility shipping on macOS. In addition to being shorter to type this format also has the advantage of allowing more than one section to be specified at the same time.
With this change
$ llvm-dwarfdump --debug-dump=info $ llvm-dwarfdump --debug-dump=apple-objc
becomes
$ dwarfdump --debug-info --apple-objc ```.