Some old mach-o core files have an LC_IDENT load command 
and there's a string in there that can be helpful in locating
the kernel binary.  Use it.
<rdar://problem/31444711> 

llvm-svn: 299612
diff --git a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h
index 6adaba9..a0006de 100644
--- a/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h
+++ b/lldb/source/Plugins/ObjectFile/Mach-O/ObjectFileMachO.h
@@ -111,6 +111,8 @@
 
   uint32_t GetNumThreadContexts() override;
 
+  std::string GetIdentifierString() override;
+
   lldb::RegisterContextSP
   GetThreadContextAtIndex(uint32_t idx, lldb_private::Thread &thread) override;