Don't build MachO2 support in lld.  This code reaches into libunwind
internals.

Index: lld/tools/lld/lld.cpp
--- lld/tools/lld/lld.cpp.orig
+++ lld/tools/lld/lld.cpp
@@ -148,12 +148,16 @@ static int lldMain(int argc, const char **argv, llvm::
     return !elf::link(args, exitEarly, stdoutOS, stderrOS);
   case WinLink:
     return !coff::link(args, exitEarly, stdoutOS, stderrOS);
+#ifdef LLD_ENABLE_MACHO
   case Darwin:
     return !macho::link(args, exitEarly, stdoutOS, stderrOS);
   case DarwinOld:
     return !mach_o::link(args, exitEarly, stdoutOS, stderrOS);
+#endif
+#ifdef LLD_ENABLE_WASM
   case Wasm:
     return !lld::wasm::link(args, exitEarly, stdoutOS, stderrOS);
+#endif
   default:
     die("lld is a generic driver.\n"
         "Invoke ld.lld (Unix), ld64.lld (macOS), lld-link (Windows), wasm-ld"
