This makes 2 changes:
- Removes unwind-section.elf-x86-64 object and the corresponding test case,
because SHT_X86_64_UNWIND is already tested here:
https://github.com/llvm-mirror/llvm/blob/master/test/tools/obj2yaml/section-type.yaml
- Removes/partially moves "No such file or directory" test, because we already have a similar test here:
https://github.com/llvm-mirror/llvm/blob/master/test/tools/obj2yaml/invalid_input_file.test