Introduce llvm-install-name-tool

This diff adds a new "driver" for llvm-objcopy
which is supposed to emulate the behavior of install-name-tool.
This is a recommit of b5913e6 with ubsan, test dependencies issues fixed.

Differential revision: https://reviews.llvm.org/D69146

Test plan: make check-all
diff --git a/llvm/tools/llvm-objcopy/MachO/Object.cpp b/llvm/tools/llvm-objcopy/MachO/Object.cpp
index 5626782..812853e 100644
--- a/llvm/tools/llvm-objcopy/MachO/Object.cpp
+++ b/llvm/tools/llvm-objcopy/MachO/Object.cpp
@@ -29,6 +29,10 @@
                       std::end(LC.Sections));
 }
 
+void Object::addLoadCommand(LoadCommand LC) {
+  LoadCommands.push_back(std::move(LC));
+}
+
 } // end namespace macho
 } // end namespace objcopy
 } // end namespace llvm