[Commands] Add a (currently empty) `stats` command.

This one will be used to print statistics about lldb sessions
(including, e.g. number of expression evaluation succeeded or
failed). I decided to commit the skeleton first so that we have
a clean reference on how a command should be implemented.
My future commits are going to populate this command and test
it.

<rdar://problem/36555975>

llvm-svn: 328378
diff --git a/lldb/source/Interpreter/CommandInterpreter.cpp b/lldb/source/Interpreter/CommandInterpreter.cpp
index cb793f7..8900bad 100644
--- a/lldb/source/Interpreter/CommandInterpreter.cpp
+++ b/lldb/source/Interpreter/CommandInterpreter.cpp
@@ -33,6 +33,7 @@
 #include "../Commands/CommandObjectRegister.h"
 #include "../Commands/CommandObjectSettings.h"
 #include "../Commands/CommandObjectSource.h"
+#include "../Commands/CommandObjectStats.h"
 #include "../Commands/CommandObjectTarget.h"
 #include "../Commands/CommandObjectThread.h"
 #include "../Commands/CommandObjectType.h"
@@ -424,6 +425,7 @@
       CommandObjectSP(new CommandObjectMultiwordSettings(*this));
   m_command_dict["source"] =
       CommandObjectSP(new CommandObjectMultiwordSource(*this));
+  m_command_dict["stats"] = CommandObjectSP(new CommandObjectStats(*this));
   m_command_dict["target"] =
       CommandObjectSP(new CommandObjectMultiwordTarget(*this));
   m_command_dict["thread"] =