[lldb/Plugin] Don't define initializers inside lldb_private

#include <stdint.h>

#define LLDB_PLUGIN(PluginName)                                                \

  namespace lldb_private {                                                     \

  void lldb_initialize_##PluginName() { PluginName::Initialize(); }            \

  void lldb_terminate_##PluginName() { PluginName::Terminate(); }              \

  }

// FIXME: Generate me with CMake

#define LLDB_PLUGIN_INITIALIZE(PluginName)                                     \