Revert "Revert "Revert "Revert "Revert "[lld-macho] Implement -dependency_info (partially - more opcodes needed)"""""

This reverts commit 3c21166a94ea02b946e9eea75c5e9bdfa8c43ae6.
The build is broken (clang-8 host compiler):

lld/MachO/DriverUtils.cpp:271:8: error: use of overloaded operator '<<' is ambiguous (with operand types 'llvm::raw_fd_ostream' and 'lld::macho::DependencyTracker::DepOpCode')

os << opcode;
~~ ^  ~~~~~~